I have this same issue with USAA, have accounts for my family that I don't want to sync. Currently I delete the transactions after each sync but its a major PITA. Prefer to be able to hide the account or choose not to sync the account.
USAA currently only allows us to permission all accounts with a single set of credentials. This feature would allow a user to "hide" an account they have permissioned.
You won't be notified about changes to this idea.