I reached a pretty similar conclusion investigating OFX to add support to Firefly III. I think best case scenario would be to setup OFX connections to the institutions that require the user to enter credentials and manually refresh data. Unfortunately you wouldn't get the benefit of automatic budgeting/spending alerts, but in my case, for just tracking spending, it would work. Right now I have to export each account to csv monthly, and import to Firefly. Fortunately the import settings are saved as JSON so as long as the format doesnt change it works well enough.

I have read in some places that you can get OFX access as an individual if you call the right customer service dept.