我不知道用中文作者你能不能看懂，但是我还是想说，大概多久可以更新1.20.2呢？

Same question here. I'll translate your question if there would be someone who doesn't know how 2 use g translate:
"I don’t know if you can understand the Chinese author, but I still want to say how soon update 1.20.2 will be released?"

Edit: sadly just modifying .mod.json is not enough(

期待1.20.2版本

I looked and it seems there have been not very well documented serialization changes that break the 1.20.2 update in a few spots. If I get some more time I will try and do a PR.

This person has a working 1.20.4 it seems, compiled and generated fine on my end
https://github.com/Galatex1/CarpetSkyAdditions