I have my changes basically prepared, but there are two problems:
it will be a breaking change...if you would want to use rotatable chests you would either need to do the migration yourself (split all merged chests, upgrade, merge them back), or start a new save
and I was waiting for this bug https://forums.factorio.com/viewtopic.php?p=696238 to be fixed first. It doesn't really block the update, but since rest of the update will be a breaking change, I didn't see much problem with waiting little more