Benjamin, from my experience the roast speed is not really going to make a big difference in the Behmor's roasts. Who cares about the color, and the window may hold a tad bit of heat in but the biggest problem is heat period, it's really straining to get enough heat to finish a roast many times with 12 oz or more in it, especially as the heating element gets older. I can not affirm this with any science but my gut feeling is that the turning on and off of the heating element during the roast is not helping either.
If the quirks of the current Behmor are bothering you, I have a pretty good feeling, you won't be satiated with the new one, and if they did fix the heat issue why not brag all over about it.
As for modding it yes,I have heard that some bypass the shit and put an on / off switch on the drum motor. turning it on and off directly with AC. I also heard of people doing this with the heating element too but id have to caution about being very careful on that one, it's surprisingly easy to start a fire in one of those, especially if you do something like that. At this point you might as well just cut out the entire control board and just run two sets of wires to the thing.. one set for the heating element, if you want to geek it, use a rheostat and one set to the motor and do it all manual. well one for the fan too. so 3 sets of wires. You could probably put a temp controller on it too, a cheap PID and just set maybe a 10 degree dead band on the temp and turn the heat on and off that way, Id use SSR's for reliability. Theyre really cheap lately.
It's been many many years but from what I remember the motor was not that hard to replace on one, so if he offers a faster motor mod, if you want to try it, it should not be too painful to swap that out.
Aaron