Don't know if this was suggested already or not

first of all - not to make the game too easy, I'm aware of that, just keep it entertaining

I thought about increasing attractivenes of % element mastery, in a way that it's not easy but when you get there you obviously have some bonuses (nothing that will make it OP).

let's use fire mastery as example:
if there was a breakpoint table of required % fire mastery to break immunities of certain mobs (Moltengrabba, Frisp) on respective levels, like 15% FM at lvl 15, ..., 40% at lvl 55+. Scaling of course can be adjusted but the point is to make someone who is absolutely crazy about min-maxing, or just regular player who happens to have a nice mods on their items try to reach this breakpoint in order to have a really small but nice improvement in the game.

Not sure about proficiencies - maybe use them as well in calculations and then increase the % you need significantly to break immunities - this would also make people try to skill profs (a real advantage in long term).

let me know, I realise this feature might take some time to implement but in my opinion is worth adding to move LS forward.