Hi, I already have my add-on on AMO. Now I want to additionally publish it from a website. Can I just download the *.xpi and put it somewhere for users to download? I’ve tried that and it seems to work, but will the updates from AMO also work (there’s no update URL in the manifest)?
Yes. Though users will have a harder time downloading directly from your website. So I’d recommend just linking to AMO, personally.