This does not solve the underlying problem at all, which makes today's MIDI, coming from a normal computer, almost unusable for serious sequencing. This is timing and jitter issues! So, may I asked, what is the actual use-case for this sequencer? I would like to see/hear some music you made with it. Or is this just for the sake of using AI?
If you have hardware synths you are going to have a decent midi and audio interface that this is not a problem. It wasn't even a problem 25 years ago.
There is no reason for consumer grade audio to be able to do this because most people will never use it.
I have maybe 20 hardware synths and I do a lot of sequencing. And yes it wasn't a problem 25 years ago, that is exactly why I still use an Atari STe! :-) But today it is a problem. It is just not possible to do complex and tight sequencing today with a normal Win, Mac or Linux computer. Even with my RME PCIe card. Your argument, "it wasn't a problem decades ago, so it cannot today either" is simply not correct.
From what I understand, midi messages can have timestamps into the future, but that implies buffering on the receiver end. Do most MIDI instruments not support enough buffering to overcome lag? Because in sequencing, the future is pretty-well known.
Yes, they have timestamps. But if you do buffer (or better to say, delay it), you introduce latency, which is even more worse then jitter. The ideal is 0 latency. And another downside with buffering, you would need to manifest the buffer time at all device you trigger to be the same time!
I wrote mine also, integrating an Akai Fire, at https://music.gbraad.nl/meister as part of a tool to do live performances. This controls some of my remix tools, mixxx and vj tools too.
Edit: my usecase is more integrating different tools and devices, Bitwig, Electribe, mixxx, my mod/protracker remix tool, etc. I guess your usecase is more to generate music, less my thing, but possible. I just have a particular sequencer/tracker use. Generation happens in bitwig
Yeah you can connect via USB MIDI using an OTG adapter by enabling "USB MIDI Peripheral mode" in Developer Options. There's plenty of videos on how to set it up from the Android MIDI Arranger App community - just N.B. you may need a powered USB hub depending on your use-case.
I use my tools from a linux machine (reliable) and Android (OK). I got a h4midi wc to improve the setup. Webmidi and JS is not idealz as wakelock is needed and javascript is actually slow.
Edit: my usecase is more integrating different tools and devices, Bitwig, Electribe, mixxx, my mod/protracker remix tool, etc. I guess your usecase is more to generate music, less my thing, but possible. I just have a particular sequencer/tracker use. Generation happens in bitwig