I think that's a great solution, if nothing else than to narrow the community you're involved with down to people who care and are more likely to help. If it makes you feel like you're around a more appreciative crowd, all the better. Hopefully that prioritizes that this should be fun and rewarding for you, not to feel like you're working for someone else's profit.
Hopefully this does 2 things:
1 - Narrows the demands of the crowd by excluding some of them.
2 - Encourages more people to pitch in financially.
If you wanted to do a delayed open sourcing, I think probably the longest delays should be in the type of stuff that the commercial shops would find most valuable and that almost no DIYer is going to replicate themselves. The production-type stuff where shops can run off their own versions of your boards. For the amateur-level DIY, the people that will be buying your boards, a shorter delay on the BOM and instructions (what they'd need to use your designs) would suffice (plus you can mark them up enough to be worth your while). I'd suggest perhaps 30 days for that, but stretch even longer to 60-90 days for the production level detail that no DIYer would realistically need.
At the very least, if someone wants to manufacture your designs without being on Patreon, they'll have to buy one of your boards and copy and recreate the physical circuit itself, create their own files to send off to their fabricators. Hopefully the engineering time on that is more costly than simply Patreon support to gain access (even like, $200/month should be dirt cheap for that tier), and being a whole season behind their not-freeloading competition be motivation enough to contribute.
Only drawback there is, for those of us that try to pitch in with documentation effort, that aren't Patreons, we'll now be out of the loop. All decisions have tradeoffs though.
I'm really curious what the non-EV but invertery-esque stuff is. I guess I'll have to be patient though
