I am not very experienced so I can’t really tell if it’s holding me back, ig I could compare the no. of reps with the one at the start of the week on my barbell rows but then again I would have progressed so I don’t think it would be very accurate

That's probably a no then. If it doesn't affect your form or limit your number of reps, I'd say just be happy with the extra stimulus for your traps. If it ends up affecting exercises where the traps isn't the focus, try to be mindful of your shoulder movement. You can also post a form check for people to give you feedback on.

Hmm, that’s a good idea actually, is it safe to clamp the plate b/w the pin and the stack?, AFAIK there is no opening on the back so I can’t put it there

That will depend on the machine and the pins. At my current gym it's possible. You can also just put the plate on top of the machine plates if those are accessible.