That’s really good news. Yes I was reading through some historical issues on git-hub about problems with the Polou step-up module and inability to set brush intervals. My 511-A seems to be functioning well so I’m assuming the Polou step-up issue is also solved.
One quick question, In your view, is the 511-A worth the extra money over the 510-B?
Edit: I also need to thank you for the 120 ohm resistor trick. So far I have tested four TTL-RS485 adapters and all of them required a 120 ohm resistor to function properly. They all work with that slight mod though!