GLM 5.3 and GLM 5.3 Flash are very different animals. The full GLM 5.3 model is what HF used to perform forensics on the OpenAI hack.

Nothing particular special about 5.3 Flash -- you might as well run DS 4.1 Flash at this point, as it's better in every way. But there is as yet no all-around replacement for the full 5.3 model.