That was just a bug remaining in the elive-upgrader (it happened too on my vbox machine). Ok so now the upgrader tool should be perfectly functional with all bugs fixed (hopefully), I suggest you to follow these steps now:
- boot in .52 live mode
- fill your HD full of zeroes with the command dd if=/dev/zero of=yourdisk bs=4M ... this will help repairing any unhealthy inode in the disk that can trigger RO issues
- reinstall .52 with auto partition mode
- reboot, use, play/betatest, and finally upgrade to trixie
- after some days to verify that all works good, you can try to switch to openrc
- IF you have again any "RO" issue or some strange error, is important to verify (before rebooting) what is happening, using "dmesg", analizing logs, etc. etc.
The tty's issue should be fixed now if you upgrade again. I think and I hope this is the final and stable version of the upgrader with everything working this time 