Can't remember who (either Mark or Johannes) I asked, but I once asked about the possibility to have an option in Axoloti to set the project bit-depth and sample-rate preferences of a sketch. I specifically wanted an 8-bit environment running at a lower sample rate thinking that it would barely use any resources of an Axoloti, and provide a genuine 8-bit processing environment.
They never said it was impossible, but if I recall, it would not be an easy thing to implement. I hear you though, I'd love to be able to create Axoloti patches in a sort of official 8-bit mode. We'd be able to create proper 8-bit samplers and huge chiptune synth/sequencer sketches if we could.
This limitation is one of only three notable issues I have with Axoloti, which are:
1 - I wish I could set the Bit Depth and Sample Rate of a Sketch and have the board adapt to it.
2 - I wish the board itself were unpopulated, and instead, featured arduino-style headers.
3 - I wish there were some multi-track full-duplex record/playback objects.
For such a young product to have so few issues is pretty damn good in my book, but unfortunately for me, it's always one or more of those three issues that stop me in my tracks.