you are right.
I have two friends who bought the first version of the Voyager 5 years ago (or even more).
They have been told that this needle valve gives a constant molecular flowrate or something like that
Anyway, you can run it like a Pelagian.
If I understood correctly, with a non fixed IP regulator, the oxygen flowrate will increase by 1 % every meter.
So you need to adjust the flowrate at the surface to match your metabolic consumption at the maximum depth.
And between the surface and this max depth, you will manually add oxygen more often that on a real KISS system.
Regards
Bruno
Yes every thing is possible tuning the mp, the flow rate to the max depth... but I prefer to kepp it simple stupid, I splach and press the button sometime....