Regarding the steer button my boards came from jlcpcb without it as well. You dont need it. The external switch works fine without it.
No you dont need external relays with the cytron modification.
You soldered the wire on the cytron to a different place than mine but like you said there are several places that will work. i dont know if that is one of them.
(Edit) Did some poking around and I couldnt find an example of someone soldering the wire to the pad you did. Yours is on the outer pad and theirs is on the inner. I think that might be your problem. Take a look at this post:
This picture from @buched is an example of an error, he said “I hope you do not wire same”.
The difference between @PotatoFarmer’s picture & @buched’s earlier picture could just be a different place for the same trace. Both report it as working. I used @PotatoFarmer’s example myself.
