I find that RAC increases just as expected, even if aborting WUs. In fact, this project seems to have an even smoother ramp as credit is granted in frequent increments rather than after successful WU completion and validation.
My 10 year old MacBook and Celeron N3150 are hardly cutting edge WU devouring monster beasts, but they're doing just fine. Even when "limited" to 96 Xeon threads you should pretty much own this project.
May I suggest the following post - it may help allay your concerns:
The takeaway (TL;DR):
o Credit is awarded hourly for processing done within workunits.
o Workunits are placeholder dummies of non-defined duration with no required validation.
o Percentage progress can be ignored as is meaningless for tasks of non-defined duration.