I doubt that it has something to do with our custom render: I've justed created a heavy project with the only modification to ./heavy/render.cpp being the addidtion of the folliwing line:
hv_vscheduleMessageForReceiver(gHeavyContext, hash, 0, "ffffffff", 0.f, 0.f, 0.f, 0.f, 0.f, 0.f 0.f, 0.f);
As the first statement in the render function
(The hash is created in the setup function)
Maybe it's because we're flooding the heavy system with all these messages? It seems to run fine when we only use 2 adc / 2 dac channels
I've sended you a mail with the vanilla project.