[nonbirithm]

Last time I tried sync with Firefox it saved all the extensions I installed but not the customized layout I used, so every time I installed Firefox I had to redo my toolbar again so it didn't get swamped in dozens of addon icons. It was always a mild pain point that disincentivized me from using sync. (But I haven't used Firefox in a while, so it may have been fixed.)

It was also pretty annoying how all the extension install pages opened in several dozen new tabs whenever sync was set up and I had to sit there letting it do its thing for a minute or two before trying to interact with anything. It didn't seem like the hallmark of a sync system that "just worked", in my opinion.

[yjftsjthsd-h]

You could disable syncing extensions?

[nonbirithm]

Yes, but I did want to sync my installed extensions, just in a way that the extension layout was preserved without further intervention, and not interrupting the initial flow with all the "extension installed" tabs. I will always want to install uBlock and my password manager in every Firefox instance, for example, so that seems like a perfect use case for sync. Plus, some extensions have a lot of config that would be a hassle to copy over every time (like Redirector).

Now that I think about it, I don't remember Sync handling syncing extension settings on top of install state.