Firefox Addon Update Policy

[stig (Stig Nygaard)]

I tried a very similar use-case some time ago.

I think this answers your question:

Is it possible to upload an "in-between" version?

Hi again So I tried… Uploaded a version 1.8.1 compatible with Firefox 56+ to AMO, and as soon as it was approved I uploaded a version 2.0.2 being compatible with Firefox 78+. When updating addons in latest Firefox version, xIFr is updated to version 2.0.2. And when updating in an Firefox 56 based “Waterfox Classic”, xIFr is updated to version 1.8.1. Thanks @caitlin. It seems mission has succeed

Of course it is some time ago, and I cannot guarantee that AMO still works the same way. But probably (?)…