That's key. If you do any DSP you do want gain matched preamps, and not adjust it at all. Particularly for Audio to Midi applications but also otherwise.
Well, that's easily resolved, you've got the source-code. It's not a hard limit.
Of course it runs, but would it be something you are confident to take on stage?
A high priority task in the host can preempt the complete VM. Then there are two schedulers: One in the host and one in the VM. Worse with two VMs. 128 spp / 48KHz is about 2.6msec. Context-switches, cache flushes, bus/device arbitration etc. worst-case that can well exceed a millisecond. So DSP load will be higher. As for reliability: Can it always meet the processing deadline every 2.6 ms for a period of over 2 hours while your on stage? Doubtful. A lot or OTS hardware can't even do that.
Anyway, if you have a Desktop (or laptop) you can pretty much run all the effects anyway (they're all LV2 plugins) in any host, no VM needed.
The real killer here is the convenience of having a robust small device, all in one box, literally plug + play that will also survive a few roadie beer attacks. It'd be great if some day a larger brother will emerge, hopefully with a similarly well spec'ed and high quality ADC/DAC stage as the DUO.