In my mind, the biggest hurdle to completing the technical diving courses is not the academic work but the physical skills required. When I took my Intro to Tech course, I was already an instructor. My first day with double tanks, learning the required buoyancy and trim, etc. was one of the most humiliating days of my life. I realized then how very much I had to learn.
About a week ago I worked with a student on Intro to Tech. He said much the same thing. He is planning to wait several weeks before our next session together so that he can get into a pool several times to work on his skills.
This is another good point.
I do not think that it's a good idea to start a tech course by switching to backplate and doubles. We had one guy in our course who did that and he left the first day. I used my doubles for two years as a recreational diver before starting tech training, by that time I was more comfortable with doubles than with single tank. Even if you never go to tech, I find the doubles configuration very stable and having the redundancy is a real plus as well. Maybe not as nimble as a single tank for acrobatics, etc... but a very solid platform.