My system is a 265k on a ASRock Z890 Livemixer WiFi. I bought the contact frame from Thermalright to see if there was any discernable improvements in thermals. The ASRock Z890 Livemixer has a RL-ILM.
Using the stock ILM = avg of 55°C above ambient on the package.
Using the contact frame = avg of 55°C above ambient on the package.
Both of the tests were done with the Noctua Nh-D15 and Gelid GC-Extreme thermal paste.
In conclusion I think the frame from Thermalright is made very well, easy to mount and is cheap af. However, the contact frame for 15th gen doesn't seem necessary if you have a motherboard that has a RL-ILM.