I’m not sure how many charge modules I already got as I used several to level other items.
But I got at least 10 so far I think.
Right now I still have 1 legendary on my main mech and an epic one each on the two secondary mechs as well as 1 epic charge unused in inventory.
These 4 are more than enough and I still keep getting some every now and then which end up as fodder for other items.
Therefore there is no need to increase the drop rates of those charge modules.
What should get some increased drop rates are the l-m only items like Magma Blast, Valiant Sniper, etc. so that more players get to enjoy those items instead of just a few lucky ones, a few rich ones or any player using underhanded means to get them.