So, I just finished a big play through with the overhaul and calamity mod using Path of Modifiers and I'd say it went pretty well overall. The modifiers and forging process give the game a new aspect as far as weapon dynamics and overall combat are concerned. Definitely very enjoyable and a mod that I'll continue to use in the future.
I was playing with DNI upgrade, more accessories, and RPG classes, so my stats were inflated. I cannot give a bare bones evaluation on life steal. Using these mods with Calamity and Overhaul I was able to out heal the damage coming at me, even by bosses with only 1% life steal. I simply plan to avoid life steal on my next play through since I believe the option to use life steal is preferential.
However, and mind you I know nothing of coding or the difficulty thereof in implementing, perhaps instead of making life stealing you could implement a type of low percentage burst heal based on how much life you have rather than how much damage you are dealing? If you have 500 life the burst heal might only heal you for 10 or 20 life with a 5% to 10% activation (Just for an example). While it won't provide enough healing to simply tank any damage coming at you, it would supplement potions and regen and maybe enough to help you win a fight you might not have. Or perhaps even make an modifier with a very low chance of activating called miracle which may only have a 1% activation, but would heal you for an absurd amount of life. You could possibly have the activation rate increase slightly the lower your health is.
Or, alternatively, you could implement a burst of high, in combat, regeneration a la palladium. Of course this is all relying on the overall evaluation of life steals' effectiveness.
The only other thing I would suggest is maybe some toggles for suffix abilities. Such as, you can not utilize the additional slow fall from feather fall by pressing up when you have gravitation. And with gravitation's fluctuating speeds you could suddenly be flung to space when you only meant to float just a little further. Also, I found an always on inferno graphics to sometimes be a hindrance in seeing other game details. Being able to toggle off the visual (Like in Luiafk's mod) would be highly beneficial. Of course, I would say toggles and visuals do not take priority over bug fixes and balancing. Just making the suggestion for future referencing.
I like the mod enough that if you were to make a support banner, I would use it. Thank you for this mod.