From what I've noticed the tunica tugs back a lot less when I haven't done length exercises in a while.
My theory is that the tugback is not from the tunica, but other limiting factors. When the tunica is the limiting factor, there is less tugback.
Take this with a grain of salt as I do not have experience with this. I have just recently stumbled on a theory that involves a third limiting factor which may or may not be true.
Anyway here is my advice... If you are getting excessive tugback, take a couple days off from all stretching and do light V-jelqs at 50% erection level followed by at least 30 min of edging. V-Jelqs are a great light exercise for length. And edging is great to improve your EQ. Both should still work towards your desired length gains.