Can you pull too hard with an extender?

So I’m just starting on my PE journey, extender has arrived and will start using it this weekend :)

However I am PARANOID about initially (or at any time tbh) applying too much tension and stopping my PE journey before it even starts due to hardening ligaments etc, been reading up on this and it’s the only thing that’s got me concerned so far.

So, if my plan is to start off VERY slowly I.e. 900g then gradually up to 1200g (with proper warm up via damp cloth) is it virtually impossible to pull at degrees of tension that would be required to cause permanent damage in terms of making my penis virtually unstretchable?