I'll bet there would be a market for that. There is just a huge amount of things to both learn and acquire to get into the process.
I agree with you about the roller size issue. Conrad will upsize the roller on request. For the larger presses, you can get a upsized top roller as large as 8-1/2".
There is no doubt that the screen technique is easier to learn and removes a variable that can be hard to pin down. Not to mention the whole debate whether you should put the ground on the plate before the tissue or on the plate after the tissue is attached....
One thing that is also easy to underestimate is the need to develop the technique and skill to consistently ink wipe and print a good plate. If you are doing this in isolation, the calibration process for your positive could be very difficult because you are chasing a moving target.
When I first learned the process, I assumed that the printing part of it would be sort of easy and mechanical. This notion could not be further from the truth. The manner in which you ink and wipe can really make HUGE differences in how your print will look. And that only comes with lots of practice. It is quite eye opening to watch someone who has been doing this for thirty years take a plate you have been struggling with and quickly and efficiently produce a beautiful print.