I'd like to study your setup. Would you be willing to share?
Perhaps a github repo of your 5 extensions or even a pastebin if you would be so inclined. I would be grateful to learn more about this by studying from your success...
I'm not the person you asked, but if they're running in their own local hardware, then it might just be a lot slower than what the big providers run their models on. System RAM is a lot cheaper than VRAM, especially if you bought it last year.