I'm in my 68th year and a polio survivor. Bad legs, so I use all the help I can get, including using my bow as a walking stick in one hand with a hickory stick in the other. My bows get abused, but I've never had a problem because of it. Adding weight to the limb with a protector CAN increase hand shock.
Anything you do to your bow's balance affects performance to some degree, whether you are able to detect it or not. Yes, I'm anal about it, but my 53 years of bowhunting have made me that way. Take no chances. My mental balance is every bit as important as my bow's balance, and anything that might introduce doubt to my shooting is eliminated, if possible. Four of the last five deer I've killed have been heart shots, from 20-35 yards. That's the bottom line for me. I haven't gone deerless in quite a while.
When I put electrical tape on my Torges longbow to protect it last year, I also added some to the top limb for balance. Negligible, I know, but...