@klh
The ability to have a user defined sound for when a number is being blocked would be amazing!

@cliffcoggin

1. The hassle of turning the phone off and then on and then to unlock the device, is too cumbersome.
2. That would make the phone useless for any incoming communications.
   I know someone who does that, but he is on the extreme of RF exposure prevention, he even uses the JRS router to reduce the signal strength and disable the beacons, but personally I still want to be reachable at least for calls and texts immediately, and for emails and IM I propose to have the data connection activated when the screen is turned on for a short while, regardless if the user didn't unlock the device, so that those communications could be retrieved, and there should also be a user defined windows of connectivity, so that it can be set to turn on the data every 5,10,xx minutes for lets say 30 seconds, and maybe even having the data only turning on depending on the proximity sensor so that it wouldn't turn on if it is in a pocket.
   Every person should have the ability to create a tailord scenario depending on their communication needs and exposure avoidance preferences.

@johndoe
Xiaomi mi A2 results:

sysbench --test=cpu --num-threads=2 --cpu-max-prime=20000 run
1717 events per second

sysbench --test=cpu --num-threads=8 --cpu-max-prime=20000 run
4915 events per second

sysbench --test=memory --num-threads=4 run
Operations performed: 104857600 (6280574.81 ops/sec)
102400.00 MB transferred (6133.37 MB/sec)

sysbench --test=mutex --num-threads=64 run
total time: 1.1919s

sysbench --test=cpu --num-threads=2 --cpu-max-prime=20000 run
1706 events per second

sysbench --test=cpu --num-threads=8 --cpu-max-prime=20000 run
5307 events per second

sysbench --test=memory --num-threads=4 run
Operations performed: 104857600 (6196075.77 ops/sec)
102400.00 MB transferred (6050.86 MB/sec)

sysbench --test=mutex --num-threads=64 run
total time: 1.1151s

sysbench --test=cpu --num-threads=2 --cpu-max-prime=20000 run
1705 events per second

sysbench --test=cpu --num-threads=2 --cpu-max-prime=20000 run
1706 events per second

@falconer78
XDA is probebly the right place to get your phone prepared for UbuntuTouch, here's a guide:
https://forum.xda-developers.com/t/guide-how-to-unlock-bootloader-xiaomi-mi-a2.3831484/
Once you'll get past the unlocking, you can start here: https://ubuntu-touch.io/get-ubuntu-touch and here: https://docs.ubports.com/en/latest/userguide/install.html

Is that even possible?

@c4pp4
Hello c4pp4
I had made some battery tests to see how efficient your method is (I didn't actually use your script), and I had found that going down to 2G does increase battery life but that having the data connection turned off is actually more efficient, and I was wonderring if you are able to create a similar script that could enable/disable the data connection, preferebley without the need to actually unlock the phone, so that when the screen is turned on it will connect to the internet so that communications could come through?
I would had made one myself but I have no idea how to.
Here are the battery tests, starting with 4G with data on:

2G with data on:

And 4G with data turned off:

You can see further details here: https://forums.ubports.com/topic/6971/wifi-mobile-data-on-off-according-to-screen-state/29

@lakotaubp
Thats correct, I would want to see if it will be possible to have the WiFi//mobile Data disabled while the screen is turned off, and then back on again when the screen turns on.
I know that there is no settings/app to do that.. It is a general question to see if it is even possible for a hypothetical app to enable/disable radios.
Apps in Android used to be able to do that, but now only rooted devices are supported.

@keneda
That's amazing! It's not exactly what I was looking for, but it's definately the right direction.
I had actually wanted to reduce unnecessey radiation, as turning the data off reduces the radiation by around 90% (-/+4%) and standby time increases by 40%-400%.
I will do some tinkering with the script and I'll post my battery longevity and radiation findings there in a couple of weeks.
Here's a graph showing radiation over a 3 hour periods with multiple phones, with and without mobile data activated.

@flohack
Using a RF meter and recording the total amount of radio activity over 3 hours.
Although I had carried the tests in the attick, and as far away from over radio sources, and the meter is not a professional one, I had trippled tested most of those phones and came with very similar results, so I'm quire certain that the results should be representative of what's really happening in regards to radio activity, and it makes sense that when mobile data is turned on, apps would comunicate with servers every so often, and that will account for the results.

@keneda
I never cared less about the radios in my phone, until a friend lost his right ball to cancer, needless to say that from beibg his regular place of keeping his phone, he would never put it there again.
Am I saying that because he always left his phone in his right front pocket, that he got cancer in his right ball? I'm not. But since then I don't keep my phone in the front pockets.
Have a look at how it actually looks during those 3 hours, and the first 10 minutes for better resolution.

@flohack
There are countless studies that prove that mobile phones can, and can not, cause cancer and other medical issues, but I had never seen a study that shows that they have any medical benefits.
And the figure of 25 years of mobile phones being around should be evaluated with the massive proliferation of radio emitting devices, and also the amounts or signals being transmitted, that are exploding in numbers, especially since the iPhones and smartphones became prevalent in society about a decade ago, and then there are the smart home devices that didn't really exist a few years ago...
I'm waiting for a sim card to arrive so I can test UT's radio activity, and I hope that I'll be able to dual boot Android on it to see how the phone behaves on both.
I think that UT should have less activity due to the reasons that you mentioned, but let's wait and see.

@lakotaubp
All of the radio tests are 3 hours and they are represented by 10800 entries for the X values, and then the Y values represent RF density in pw/cm².
I'm not a RF Engineer so pw/cm² doesn't really mean much to me, but when I use Excel to view all of that data in graphs, it becomes easy to see the differences between devices, so here is the Xiaomi mi A2 UT with data on in grey, and the Pixel 4a 5G (using LTE) also with data on in blue and data off in orange:

Here is the same Pixel results, but with the mi A2 without a data connection represented in grey:

And here is how data off looks like for the Pixel in blue, mi A2 in grey and a Redmi 9 in orange:

So you can see that Xiaomi phones have more spikes and of greater energy, but I had seen far worse results with a Huawei Mate 20 Pro represented in yellow:

And here's again the first 10 minutes from the Pixel test:

and another graph of seconds 70 to 200, where background RF radiation is grey (no phone):