Thanks for your answer, it clarified things a lot.

My concern with plaid.com using my banking credentials on an ongoing basis still stands though, and for me this currently outweighs the privacy benefits to be gained by using the service. Additional ways of funding (either using a debit card or ACH preloading) would be most welcome and go a long way towards addressing my concerns.

privacy.com would be a very useful service to me, and I hope you will be successful with it!