With vkQuake on macOS (qbj3 and id1 in /Applications), I get "HOST_ERROR: Model progs/v_axe2.mdl not found"... their docs say if it's not ironwail then "expect issues". :-\
I used QNX in the 2000s at NIH to run experiments! We eventually replaced it with Linux and Windows and dedicated "experiment" hardware to handle the "real time" needs.