so what could CCP do ?
Well first they could stop that nonsense “-20%” which actually hurts the highest resists the most. A mix of -5% AND -5ppc would actually achieve similar results for lower resists, and similar impact along the high/low resist bonus.
eg a -30% resist would become -(30*0.95-5) = -23.5% (instead of -24%)
a -64% resist would become a -55.8 instead of a -51.2%.
Second they could, very simply, BONUS the local rep.
That means +20% rep/cycle for local shield, hull and armor repairer/booster (yes, also hull. they are bad, make them less bad).
That also means -17% base shield recharge rate to increase passive shield tank without increasing the buffer (so +20% regen)
THEN they could adapt the heating bonus : add a raw ppc instead of a percentage. So the invul overheat goes from 30->50 instead of 30->36. and a -64% hardeners is increased from -76.8% to -84%.
FINALLY of course change the DST to make them bonus apply to the raw ppc - but reduce it to not reach 100%.
ANOTHER good thing to do, would be to replace the [layer][type]resist attribute by a [layer][resist]tankiness attribute : a module that provides ONE point of tankiness multiplies the EHP and ERP by two , ie resonance = 0.5^tankiness . so a -50% resist module would instead have tankiness=1. a -29.7 em resist module would instead have em tankiness = 0.5, etc.