I have a couple of ‘hand’ trimmers. This one, similar RCBS one and Lee Quick Trim (which is just remanence of bad decisions when 308 was all I wanted). When I am doing something that requires a little more elegancy with my operations, I’ll still use the hand cranked one. For everything else I am lazy. So, saw this for $50 a while back on FB and thought, yep…
Drilled, tapped, screwed a bolt in there and BAM!!!
…automated 
I’m thinking, some sort of belt/gear solution and a spring to push the cutter back, to remove that manual movement as well, is on the cards 
Have it on rails/runners or something. Just a brain fart at the moment.
N.B. I wouldn’t make a permeant mod like that to my trimer other. Hence the second one… Well worth a fiddy.