Just to keep you up on the subject from the old thread:

I've had only one crash of email the whole week and didn't reboot for about 7 days. Seems it got fixed by deleting the local cache files.

Just as I was about to turn offline IMAP back on, the new release was available, so there's no reason to keep testing the old
Still I did delete the cache folders once more before turning offline IMAP back on. Haven't had any crashes the last 24h.