we use an almost identical circuit like pmp11612 and our snubber temperature reach 95° C under full load.
only difference is the fet: datasheet.lcsc.com/.../Wuxi-NCE-Power-Semiconductor-NCE65T1K2I_C181922.pdf
and regarding to the design files, the snubber only reached 75° C while testing from TI.
is our transformer leakage too big? we made custom transformers based on the sumida 10339 - t048 sheet.