Yes! Finally successful in getting my #dotnet7 #Blazor app to import #Mastodon Lists from a csv backup file.
It's nuts how there's actually NO W3C standard for passing array-parameters in a query: https://stackoverflow.com/a/67095427 . It's framework dependent, and is PHP dialect here.
https://docs.joinmastodon.org/methods/lists/#accounts-add wants an account_id array, but NOT in json which would be more concise.
Instead, it's fat pairs of literally { "account_ids[], "<account-id>" } for every account to add!