Long ago, there was one similar to what you describe....can't remember the brand, but it was expensive and not an easy install. Antiquated by today's standards.
From dissatisfaction descriptions of your controller....well, that's an old and cheap bottom line one you have, or have used in the past.
Tech has come a long way since then.
You just need a proportional output controller, like a Prodigy. Simple, easy install, works perfectly. Once you adjust the gain, it works flawlessly, applying more trailer brake action when you need it, far less when you don't.
There's no more violent jerking at slow speeds, when you've got it cranked up for highway speed stops. And yet, at hwy speed panic stops, it kicks out the voltage to help shut 'er down, effectively and without loss of control.
What kind of trailer and what kind of brakes does it have on it?
Diff being, you may need the Prodigy-3 vs the basic model.
2007 LBZ 3500 LT3 DRW Crew Cab, Sulastics, Putnam XDR 15K, B&W 30K-Turnover GN+Companion, Ride-Rite Air...EFI'd by Rob
2008 LMM 3500WT DRW Crew Cab, 8 'Flat/GN, Workforce Alum Toolbox, Ride-Rite Air Use-ta Haves 2006-6.0 3500 WT DRW ExCab Flatbed, 2005-LLY 3500 LS DRW Crew Cab, 2002-LB7 3500 LS DRW Crew Cab I Live my life in such a way that when my feet hit the floor in the morning...Satan shudders & says "Oh shit, he's awake!"