You don't need to switch. You just won't be able to set up a new sdcard as adoptable storage starting with the latest build.
Already existing adoptable storage continues working (of course with its bugs...).
That's what I suspected, but thanks for clarifying.
---------- Post added at 06:37 ---------- Previous post was at 06:25 ----------
This workaround "fixed" it! I rebooted a few times and now I am equipped with 144 GB device
It's fairly straightforward to figure out whether it will work.
After rebooting, go to 'settings ... storage' and if it says 'checking' on the card, give it time and it *might* pick it up.
If it changes after the above to 'corrupted' and there's a weird second card listed as 'not inserted', *you need to reboot*, and do it until it picks up the card again properly and there won't be a second card listed and the storage will reflect your combined card and phone storage.
The max number of times I have had to do this is three times. Once.
As a result of these 'corrupted' starts I HIGHLY recommend good backups. I've not ever lost something, but with this bug you can never know.
Finally, these dodgy starts seem to cause 'tombstone' files that you need to clear using the repair command in TWRP. (Interestingly, TWRP [3.4] never fails to load the adoptable storage partition properly). You only need to tick the data partition and it will also check the adopted storage on the card, too.
