While I agree with Invasion being way too time-consuming, mods are a HUGE power boost that you’re missing out on. Even +10 skill levels are enough for a sizeable boost, and it’s possible to add over 100 to a single skill.
EDIT to prove my point, here’s Jafar’s “Whirling Dervish” when fully maxed:
And here’s “Whirling Dervish” with +50 blue skill levels, which requires the amount of upgrade pieces from a single Invasion:
Last I checked, it’s possible to add up to 160 levels (40 per mod). Definitely not useless.