That's what I did and replaced my controller with a 25 amp KT controller, and it was actually cheaper than the Das-Kit replacement.
But I still prefer the Das-Kit.
It's WAY better built and engineered. The controller itself is fully potted, it's in a solid cast aluminum box, and is completely waterproof.
All the Das-Kit components are better built and more durable.
The ONLY thing that I didn't like about Das-Kit was the power delivery, and when I touched the throttle or the PAS mode engaged (after I start pedaling) the bike went to full power to get me up to the PAS mode speed setting.
I HATED that.
My Das-Kit powered Et.Cycle T1000 is built like a tank and can carry a 330 pound rider and needs all that power for a heavy rider, but you can't turn the power down.
I almost launched my e-bike into my neighbors backyard when I hit the throttle, so I installed the KT controller which allows me to adjust and control the power.