Additional questions for you to consider, in part selection:
- is the current "DC", changeable or modulated (signal)?
- does the larger system prefer analog control, or serial digital?
- how accurate does it have to be? I see up to 3 significant
digits on some values, implying 0.1% range accuracy but
think this is not likely really the case.
Switched resistors could be a simple and foolproof approach
if the circuit is operated linear - you're going to waste current
anyhow, same difference. And if "aerospace" means "space",
the relative ease of finding radiation tolerant COTS switch
devices is sure higher than finding an analog part that
doesn't drift unacceptably.