I think it would be really hard to filter through all the posts to figure out who is working on what. I think it would be better suited for someone to put this in the wiki on the UPM github page.
The best way to make sure that no one does a UPM sensor you're working on is to do release some code quickly and get a pull request on github in early and keep updating that branch until you're ready for someone to merge it in.
If you'd rather not do that then you could open an enhancement issue on github, assign it to yourself and say you're working on that sensor
Brendan Le Foll
FYI I dont know of anyone working on the SSD1351.
Thanks for comments - was not that into github (but am a bit betterer now).
That does seem the best way of handling it - I have put an issue in for the adafruit controller and hopeflly it will get assigned to me (I don't seem to be able to do it myself).