Would it be possible to have a following on the Carddav issue?
I wrote my feeling in here about this topic : https://forums.ubports.com/topic/4486/a-shop-ready-to-serve-for-ubports
that I copy in here, hoping it will be read.

More and more people are syncing their contacts with clouds like nextcloud and they rely on such feature.
It is not possible to offer professional to switch to UT without this feature.

An issue is open here ; https://github.com/ubports/address-book-app/issues/3
and an other here : https://github.com/ubports/sync-monitor/issues/9
and commits have been made in here https://github.com/ubports/address-book-app/commits/xenial_-_mercontacts but none have been merged.

I feel like this feature isn't considered very important by devs (I guess they have no problem with the script) and I respect their work and choice between priorities. However today, I don't feel good. I follow UT project since it has started, I'm asking for this feature for long, long before Canonical gave up and I kept asking for it for the past three years.

I supported Firefox OS...
I supported UT...
I bought BraveHearyt Pinephone to do testing, and now a PineTab for my mum. Can I ask my mum to sync her contacts with our nextcloud using a script? Seriously?
I don't see why this very basic, important widely used feature is so considered as a leftover and in Q&A it is always question about MIR, Lomiri and other very very specific geeky things that not my mum, no other daily users need.