Bill Tindall, E.Tn.
I am in favor of anything that enables someone to get the job done. However, crutches (or training wheels) eventually get in the way and they will be abandoned for the sake of convenience. I predict that by the time you work your way through a few drawers this jig that seemed so necessary and useful will be used no more. (then you can pass it on to the next woodworker climbing their way up the learning curve)
One thing the jig prevents is the beneficial first chisel chop that I use. For the first light tap of the chisel in the scribe line to establish a shoulder I angle the chisel away from the scribe line( about 5 degrees)This approach ensures the chisel does not nudge the shoulder past the scribe line. The next whack on the chisel can then be more robust.
I'm working on 8 drawers with 9 more scheduled. By the 8th I will be getting both quick and accurate. By the time I start the next 9, months will have passed and I'll have to regain the proficiency I had on the previous 8th drawer. I have made peace with the fact that only other woodworkers care if drawer dovetails are flauntable and don't bother striving for this level of perfection. The drawer will be judged by the user by how well it functions. Fit is where to spend the effort.
BTW, I like to undercut the end grain just a bit. There is no useful glue surface here so there is no reason to get it perfect. Undercutting not only ensures that the joint meets at the outside edge, but it provides a place for excess glue to go instead of squishing out into the expose corner.