Sounds like a Brake Buddy "Classic" which does not offer "proportional" braking. We had one of those and didn't ever feel that its responses were excessive. After a number of years, it got erratic and we sent it back to BB. They said it wasn't repairable and offered a discount price on "Vantage Select" which IS proportional. I really don't see the need. Another OP here, sent his Classic in, and was offered the current Classic model at discount. That price was a lot less than I paid for Vantage Select. If I'd had the choice, I'd've gone back with another Classic.
So if Classic's what you have, use it and you'll be pleased. There's an air pressure setting based on the weight of the toad. Then from there you pick the sensitivity (responsiveness to deceleration because RV is braking).
Be sure to run a dedicated power supply from Battery to Socket for the BB's power plug. If you call BB and tell them you need one, they'll send it, free. If you rig one yourself, be sure the socket is METAL. BB pulls enough power that the plastic ones will distort.