I gave up on rugged phones for this, I got a pixel 5 and a rhinoshield, which has survived over a year so far, although I don't just throw it around like I could with the bv7000. that phone was the smartphone equivalent of an old Nokia 3310.
All Blackview and CAT models were insanely bad when it comes to their software, and I couldn't get them to run any self-built ROM and neither any GSI image so I gave up on my dream of an open rugged phone, too :(
In the BV case I even tried using the MediaTek root-mode exploit, but didn't have success booting any compiled kernel because lots of drivers are messy in their firmware.