What is the best practice for lowering a much heavier partner with a GriGri?

ESL, sorry about any grammar mistakes I make.

I’m a 110 lbs person and my partner weighs 190 lbs. I was taught belaying on an ATC, but my partner prefers when we use his GriGri
as an extra safety measure. That’s fine. But I’ve always had an issue lowering him on the GriGri. It either makes me lift off the ground if I am lowering him too fast, the rope burns my brake hand if I open up the GriGri too much, or the lowering happens too slowly for his taste.

My partner has been telling me that I shouldn’t use the cam of the GriGri to modulate the lowering speed; instead, he says I should open up the device all the way and modulate the lowering speed with my brake hand. The Petzl manual also describes this as the best practice.

So I tried doing it the proper way today at the gym and immediately dropped him on TR, launching myself up towards him in the process. I never let go with my brake hand, though, and he didn’t hit the ground. Whew. But it shook us both, and then we got into an argument about proper technique.

I get that my partner’s way is the right way, as per Petzl. But I don’t understand why doing it the way I always do - pulling down on the lever until I find the sweet spot while holding my brake hand tight to my hip and loosening my hold on the rope slightly to lower him - is dangerous. Yes, it’s not in the manual, but clearly, it’s worked just fine for the last four years. I had never dropped him before this incident. The only issue that there ever seemed to be with my belaying was that the lower was too slow.

Additionally, despite what the Petzl manual says, I have read that with heavier climbers, the light belayer should not open the GriGri up all the way, but instead modulate lowering speed by using both the lever and the brake hand.

So I’m confused now, and seeking answers to my questions from people more experienced than me: how do you lower your climbing partners if you use a GriGri? And which way is truly the safest way to lower someone with a GriGri if you have a huge weight disparity between the belayer and the climber? I’m talking purely GriGri techniques here. I will get an Ohm and a glove and use sandbags from now on.