https://series.ultimatecup.racing/
I had noticed this series (of series) earlier on but never paid attention to it, however now that I'm looking at it, it may be somewhat interesting for lovers of prototype racing. Not only do they have usual stock LMP3 series - which will have upgraded 2020 chassis options available next year even before the actual ACO championships (& Oak Ligier JS P4 thingie from the Ligier Cup functions as secondary "P4" class) - but they also have a CN series. Which by definition should be among the very last open technology, unbalanced sportscar category left after the demise of LMP1. I appreciate CN not dying quite yet.
The individual sub races are not sprints either but several hours long, and in addition to French there is some english commentary:
https://youtu.be/UvCNI6IS3SM
Entry lists are pretty small from what little I saw and I really think they should integrate CN into the LMP3(/"P4") "Prototype" grid, but anyway I think next year might be more packed when the upgraded P3s come over
They all also have Michelin spec tires which is boring but then again all series have that curse nowadays (except SGT and rare others)
UCR has the backing of ACO but I didn't put this under the ACO regulated series as they're not the organizer