Normally the Axoloti runs the uploaded patch from the internal RAM, a large portion of which is reserved for this purpose. Even when 'Upload to internal flash' is selected in a patch, if I understand correctly it the patch is stored in flash, but runtime is executed RAM just as usual, i.e. the flash is just used for the actual storage.
I had an idea: how hard would it be to run the patch directly from flash. I.e. something along the lines of reserving an area of the flash for the executable patch, and flashing it there when uplaoding, and actually run it from there. The advantage would be that more (fast) RAM would be available for longer delay lines etc, if one doesn't want to use DRAM for whatever reason. The downside of course is that it takes longer write to the flash than write to RAM, and also writing to the flash causes wear on the flash, so it's probably not for everyday use.
The Axoloti very obviously can runtime write to the flash, as it can store a patch there, so it would mostly seem to be an adjustment of the linker control file for where things are stored, and also a portion of the flash must be reserved for the runtime patch and uploading a patch must cause a write to that area. Is there anything else I'm missing?