Minor bits and pieces can get out of date but to be honest, Stripe's documentation is really good and their engineering team is great about helping users fix issues like you've had. I don't think it's unreasonable for Chris to have separate Master Classes. I've been a GoRails subscriber for a while and I purchased the course and have used it on a few projects now.
If you're like me and got yourself blocked from your site by testing Fail2Ban out just type in
fail2ban-client unban <yourIP> or
fail2ban-client unban --all.
I ran into this issue when going through the same course recently on Rails 5.2. local: true definitely fixed it. Thanks guys!