One interesting morsel in all of what you described is that for all of the hoop-jumping SpaceX does to bolster rt-Linux, it is -still- easier/faster/ better by some business metric for them than the alternative.

If the redundant hardware and some ground rules they have in place have made the onboarding of developers better and faster, than perhaps it should be recognized that they seem to be prioritizing the DX - especially since plenty of applications in RT will also use redundant hardware and confine their hardware selection similarly to prioritize the performance targets of their application, SpaceX just added developers to the feature matrix.