If it is a closed channel shouldn't you have the option to send it via on-chain?
Yep, but it apparently went to a different wallet derivation, as the FC should go to a taproot address, not a native segwit one. Still trying to figure out why that happened.
Also, what is the methodology for some of these wallet closing channels?
I think Blixt is pretty much using LND "rules". As for Breez, not sure, but I guess they are using Greenlight/Core Lightning 1 as of today.

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