SO I assume Intel makes them all t the i9 10900K spec then depending on testing they bin some down to 10900 spec. Since 10900 will be more common that 10900K it is safe to assume some 10900 chips will run fine as 10900K chips. I woudl think that since even a 10900 has to run at 224W for PL2 that it should be rather safe to set P1 to 125 and leave P2 and tau alone and get near 10900K performance in a 10900 SKU. I would throw a Noctua NH-U14S on it with the second fan and I bet you are fine. My Ryzen 9 3900X with that HSF with all cores pinned at 4.1GHz for 20 min runs about 125W and never gets above 72-74C in a room that is a tad on the warm side.