I've been working on an "extended bech32" format with 12 character checksum rather than 6, for private keys and other things that need stronger protection. It would guarantee correcting 4 errors, where normal bech32 can only detect (but not correct) 4.

The rationale is that in the case of an address, if an error is detected, you can ask the receiver for a corrected version. As that option doesn't exist for private keys you want something stronger.

This has been a low-priority thing for me, though, and the computation work to find a good checksum is significant.

Cheers,

-- 

Pieter