Ugh, now that I've skimmed that, it looks like it's still a major pain in the ass. With Firefox fading fast, you'd think they'd be a little smarter about enabling features that make it competitive.
Aaand now that I've tried your page and another WebMIDI test page mentioned in a Firefox issue with Firefox 101, it still isn't working. So I don't know where that article is getting all that.
I sympathize with your complaint about Firefox, though. But check this out: https://blog.karimratib.me/2022/04/23/firefox-webmidi.html
Ugh, now that I've skimmed that, it looks like it's still a major pain in the ass. With Firefox fading fast, you'd think they'd be a little smarter about enabling features that make it competitive.
Aaand now that I've tried your page and another WebMIDI test page mentioned in a Firefox issue with Firefox 101, it still isn't working. So I don't know where that article is getting all that.