Crash safe visibility map vs hint bits

There has been a lot discussion about index-only scans and how to make the visibillity map crash safe. Then followed by a good discussion about hint bits.

What seems to be the main concern is the added wal volume and it makes me wonder if there is a way in-between that looks more like hint bits.

How about lazily wal-log the complete visibility map say every X minutes or N amount of tuple updates and make the wal recovery jobs of rechecking visibility of pages touched by the wal stream on recovery.

This seems a lot like the checkpoint mechanism but I can't see if it can just follow the same pattern directly.

This may also just demonstrate my total lack of understanding of PGs intervals.

Jesper