I was listening to a podcast with Eric Grauffel yesterday. He says put your finger where it's comfortable for you based on your anatomy. It was very interesting to hear his opinions. Many of them were contrary to commonly accepted practices.
I'd take any opinion like that before any "DO THIS". I didn't use the pad of the finger when I used a glock 17 and I had much better shots using the first joint in any kind of shooting
Amen! Reminds me of the one thing that irritated me about my concealed carry class back in 2015. They had us practice grip and stance with dummy 1911's. I have wrapped my left index finger over the trigger guard for 20+ years, ever since I got my first 9mm (probably did it with my 1911 when I was in the Army, but I can't recall as I only carried one for a year and then started lugging an M16). I notice 2 of the instructors staring at me, and then one made a beeline for me and told me that was an 'incorrect grip'. I mentioned that I had been using it successfully for 20+ years. His reply was (I paraphrase) 'well, you need to change it if you want to pass this class.'
Granted I have subsequently had to adjust for my pistol with a light on it, but I'll never forget that narrow "only one way to do it" mentality.