I've known of some engines with adjustable pushrods, but would you run adjustable pushrods in a 7K rpm BBC?
I agree with you that the servo doesn't see the stresses of a pushrod.
The adjustable servo pins look nice and are innovative but do you really think they will be a hot seller?
I'm all for new stuff that works and I can appreciate the effort that goes into it since I'm working on some stuff for the 4L80E and TH400 myself. However I don't see myself as a builder buying any of these.
I guess it would be handy to buy one of each, use it to set band clearance, measure it, then make a regular servo pin match the length. Much like you do building engines and using an adjustable pushrod to figure the length to order.
The other possible issue, I've ran into sometimes, you REALLY should have a cover with a hole in it ( and I think your pins come with one from the pics I saw elsewhere) so you can see the servo travel, but the cover has to match the servo you use.
If building a 200-4R, and if you used a xxx brand servo on every build, it would be worthwhile to buy one to butcher and use as an assembly tool. However I use a different servo depending on level of build, so I'm not buying $500 worth of servos to butcher.