This very useful when creating SuperTag, but on nodejs setup, it will make tiddler become JSON, and will not delete the .meta file. So after restart, it will regard the JSON as text

This very useful when creating SuperTag, but on nodejs setup, it will make tiddler become JSON, and will not delete the .meta file. So after restart, it will regard the JSON as text

Yes. Multiline fields have to be saved as JSON tiddlers. We do not have a .tid file format, that can handle multiline fields.
and will not delete the .meta file. So after restart, it will regard the JSON as text
IMO it’s the responsibility of the core syncadaptor to handle that. It’s the syncer module, which switches from .tid to .json.
I did the following tests
TW Node.js configuration using editions/tw5.com-server
test.txt
text/plain
some text
which creates 2 files. A tiddler.txt and tiddler.txt.meta file. → OK and expected
test field and saved the tiddler.It switched the file-name of the tiddler to test.txt.json and removed the text.txt.meta file. → OK and expected.
I did also switch back and forth removing and adding a multi-line-field. Everytime the .meta file was handled in the right way.
So if that’s not the behaviour of your edition, it may be problem of your sync-adaptor.
I’ll move the issue to a new thread, because I cannot replicate the problem with a default Node.js configuration as described above.