I've loaded for my Glocks since day 1. Won't have a gun I can't reload for other than rimfire. I have loaded cast bullets despite all the flak I heard from others about the pressure problems with octagon rifling. Of course I never get wild about trying to make hot loads. I've loaded for 9mm and .40 Glocks for like 20 years with no issues. 5.2 gr Unique with 122 gr Widener's hard cast bullet for 9mm. I can't remember my pet load for the .40, but it uses Unique (5.8gr maybe?) also with the 170 gr Widener's hard cast bullet. I use Speer Gold dots for my serious stuff. I don't buy factory ammo at all. But remember the #1 rule-back off the loads and work your way up, and don't believe ANYthing you read on the internet (including this) until you prove it for yourself.
Titegroup, Bullseye, Accurate #2, etc are all excellent powders, but these fast powders can go from fine loads to potential Kaboom with just a few tenths of a grain difference in load. Plus a single case will probably hold like 5 or 6 full charges of this stuff without running over. All I'm saying is please be extra careful and pay attention to detail with these powders. I was shooting some .38's with Bullseye, and did quite well at 4.0 gr behind a 158gr cast bullet. Bumped the charge to 4.2 gr and locked up my S&W 36 with a swelled case on the 3rd shot. I can imagine if I'd gone up half a grain.
I side stepped the unsupported web issue by purchasing a Bar-Stol barrel on my 40. Not sure if Glock ever changed the design on the 40's chamber to address this issue. It was the 40 cal only as I remember. Watch for bulges in the web area of your cases.
You are absolutely right. These fast burning powders have very sharp pressure spikes. When you begin to see signs you need to stop immediately because you are fixing to have problems. For pleasureable shooting though you can't beat fast powder and heavy bullet.