I recently had a question which I wasn't sure if this would be the correct site for as it seemed too speculative. But by the time I completed it, it seemed, more concrete than I'd imagined. I would like a second opinion of which site it belongs to before I post it (and delete the other as cross posting is not allowed)?
Your question probably would belong on physics.SE, if it wasn't ill-posed and unclear:
The "state reduction" or collapse of the wavefunction is a feature of certain interpretations of quantum mechanics, and there exist interpretations that explain the results of measurements other than with collapse. Failure to mention this when talking about modifications of quantum mechanics indicates prior research is lacking here, and makes it unclear what you mean by "modifying R" when R is not even present in all interpretations.
It is unclear what you mean by "It seems to me everyone in the physics community has been working on modifying U". The large majority of the physics community accepts conventional quantum mechanics as correct and does not work to change it at all.
For these reasons, I would close your question as unclear what you're asking regardless of its on-topicness otherwise.