Both Windows versions of SFNNv9.5.3_240420 are released now with new default parameter for Mediumnet threshold of 1200. Old value of 300 was just a (dumb and wrong

Use 1200 in SFNNv9.5.3_240410 or even make selfplay tests with different values to find a good MnTh parameter (to find the optimal one takes 10000s of games). Anyway, the optimal value of Mediumnet threshold (MnTh) depends (not that much on the same OS) on hardware and also on TC. Both dependencies could be minimized by empirical formulas, however 100000s of games are needed

However, with one(!) good MnTh value Stockfish dev can be easily beaten at STC and LTC. Here are the three tests with MnTh=1200 on my mini PC with Celeron N5095 (modern builds):
https://github.com/Joachim26/StockfishNPS/releases
Thank you Joachim26 !