IMHO, this is exactly what has been happening with regard to Motion Flow and the Low/Standard setting. It limits processing to specific artifacts while maintaining the overall aesthetic. Could it be better? While I will say yes and I would love to have more user control, I have to say it has gotten better.
Rather than have the argument that frame interpolation "sucks -vs- doesn't suck", I'd rather be more constructive and have a conversation that gives guidance regarding any new coding Sony might attempt. Your comment about limiting the process to specific conditions is exactly the conversation that might help improve a future version of Motion Flow.
I don't know enough about how the process currently operates in LOW versus HIGH. I'm sure R&D has been struggling to address this very issue and it all comes down to cost/performance and what degree of processing is needed to get to the next level. IMHO, the performance has reached a point where they should try to offer user adjustable "sensitivity" to the current LOW/HIGH settings of motion flow.
As others have noted, Back Light strobing is offering a new solution, and Clear and Clear Plus on the hx929 not only works to reduce artifacts, it is also brighter when engaged as compared to other Sony displays or Dark Frame Insertion on my vw90.