Don't bother simming mods unless you have the 5* version open.
Sim & Sell most of them, keep mods that are 5*, have Speed on them, and have logical Set/Primary synergy for the Arrow/Triangle/Cross.
Like Defense Sets w/ Protection, Health, or Defense Primaries.
Or Offense Sets w/ Offense/Crit Damage primaries, etc etc.
A Defense Triangle with Offense Primary isn't going to have many characters that want it.
If you can afford it, do 3 refreshes every Tuesday/Wednesday on "All Energy" days.
The other 5 days too if you can, Mods are HUGE when it comes to beating events & PVP.
You can't get gear back that you give a character, but you can swap Mods around to use your best ones to pass an event & then replace them w/ lesser mods after you pass it.