Little the same as i wrote on github https://github.com/ubports/ubuntu-touch/issues/860,
Also please understand, we are a small team with a huge task, we have many moving parts and moving to a newer version of mir and unity8 at the same time is not helping, we are doing our best to make an an awesome operative system. but we are in a really busy period after taking over from canonical, we updated to xenial, we are updating mir and updating unity8 all these are huge since canonical left it all the current version far behind the latest releases, this forces us to make major changes. We are also building Halium and following the evolving of android and newer devices to be able to follow the mobile marked. At halium we are also trying to move our sensor, gps, media and camera system over to an active maintained system instead of maintaining our own. And we are also looking at merging our patched in celluar and pulse with an active maintained one. Once we move things to active maintained systems where we can work together to get to the same goal, we will then get more time to focuses on core functions.
About replacing the browser, this is an huge part for us, we are not able to maintain our own fork of chromium (oxide) that why we are forced to move the browser, this move will in fact give more time to focused on the core functions on the phone.
We are moving to newer version of pretty much every part of the system, this is a major work. Once we have done the major upgrade we will get a lot more time. And in fact we are really close go get to this point, we now are super close to finish all the mir/unity8/libhybris upgrades. And we don't have a big enough team to focus on all the bugs right now as the code may have merge errors to be able to merge with never version and to risk spending lots of time on bugs that might be fixed in newer version. that's why we are upgrading, getting our source aligned with newer sources to then focus on fixing and improving.
In fact most of these bugs comes from the canonical days, they was a much bigger team then we are right now, so we don't work at the same speed.
We are doing our best with the small team we have.
OTA 8 will include new mir and unity8 (and many other updated parts), we hope these have many of these issues fixed, but we have to expect some bugs to be included also since the upgrade is so major.
Thanks for understanding ;)