The humans already are out of market making. Most guys just set the vol levels and their software trades for them. They are pushing quotes. The beauty of options vs stock and the HFT's is the way orders are dispersed. If I'm bid for 100 at 1.00 and Citadel is bid for 100 at 1.00 and a 10 lot retail order hits our bid, we each get 5 lots. Citadel has no edge over me in that regard. Whereas in the HFT world Citadel would jump ahead of me and take the order. So these market makers still get the order flow. The problem is it gets divided up among so many different players. So there is money to be made there but it's a much smaller pie. But to answer your question, everything already is automated.
Maverick seem to match exactly what you're describing, overnight margin on option spreads. I've been thinking about joining them for some time now, and will likely sign up with them by end of the year. I've looked everywhere and was unable to find ANYTHING negative. If you guys know of any "horror stories" or really any kind of info on them, I'd really appreciate it, otherwise the place sounds great for my trading style (premium collection/positive theta strategies)