Addon with optional Native Messaging permission - will it install

I have an addon which is used mainly on desktop but I run it also in Fenix nightly.

I added a feature which uses native messaging, which is an optional permission. This feature obviously can’t run in Fenix but that’s OK.

Question: if I update the addon in AMO what will happen in Fenix? Will it
1 Update and work OK - provided I don’t select that feature?
2 Fail to install and leave the earlier version installed?
3 Fail to install and remove the old version?

If the answer is 3, how can I get the old version back into Fenix, given that I cannot AFAIK add an old version of an addon to a collection. Or can I?

This issue: says it’s fixed - but if I try to install an addon with (non optional) native messaging it fails to install - though it doesn’t say why. (This addon

Does anyone know an addon I can try with optional native messaging permission?