The strongest LGA 1200 SFF (with SO-DIMM) is actually the new Asrock Deskmini H470M-STX, while Thin Mini ITX has B460 at maximum, likewise from Asrock. Asus offers a lone H410 Thin Mini ITX board.
In recent years, I only bought SO-DIMMS, so I am only interested in mainboards which use these.
Also, I don't like internal power supplys. They are just heat sources which need additional ventilation, so I prefer power bricks outside. These days, with stronger iGPUs, I only accept one fan in the system for the APU, and which I want to be as quiet as possible short of a fanless system.
So the STX format is just right for me, but manufacturers are not convinced of this market.
Because I lost patience in waiting for SFF Renoirs and Tiger Lakes, I went the NUC route and transformed a NUC10i5 into something rather quiet:
