I bought a new MyPhone Maestro+ mobile phone. I haven't tested it much yet, so I don't know if this will become my main phone or my spare phone. It's dual-SIM and has a decent keypad at least.

After the fiasco described in the parent post, the first step in testing a new phone is figuring out how to copy contacts to it. So here are the instructions for how to convert your phonebook so that this phone can read it.

Export the phonebook to the SD card of your old phone. Copy the file onto the root directory of the SD card of the MyPhone Maestro+ and name it Contacts.vcf. You can use either an external SD card reader for this, or just connect the phone to a computer with an USB cable and it behaves as an external drive. Then, on the phone, choose “Names” then “Options” then “Phonebook settings” then “Restore contacts”.

That's it. No need to convert the savefile. The savefile from either the Nokia 216 or CAT B30 work just fine. These saves aren't the same format, I had to convert from one to the other to be able to migrate to the CAT. And it's three different brands. Finally someone figured out how to make good phone software that's not picky!

(You may have to delete your existing phonebook on the MyPhone, because the restore operation merges the contacts by default.)

Update 2022-04-04: Ok, here's the bad part after testing the telephone a bit. There is no way to write accented letters when the user interface language is set to English. No separate writing language setting, and no accented letters available in the English input mode.

Update 2022-06-21: Above claim was incorrect. It is possible to change writing language separately by long pressing # when writing text, and this solves most of the previous problem. Perhaps I didn't find this when I tried earlier because the long press needs to be 2 seconds long.