Have we move past the IC vs Sup difficulty?
I am not familiar with ICE and this might be impossible but if its not:
tl;dr version:
Why not make IC miners have their own hull class. Make this hull class especially vulnerable to Galvs.
The way I see it we have One tech path shared by all factions (Sup) Having trouble with one faction(IC) invulnerable(or incredibly resistant) to one weapon(Galv) in these factions.
This seems to mean we need to nerf something in IC in relation to galvs.
These options seem to be the most viable:
1 Make IC bases galvable
2 Perk Galvs in some other way vs IC only(All of these would require a new IC specific armor class, this might be impossible if it is I'm sorry, and some variant of 1 may be neccessary).
-Any one type of hull vulnerable either: basic ships, bass killing ships (ie bombers HTTs), or a type of utility ship.
Of these options 1 seems to be ruled out by Faction Uniqueness. When balancing something it is arguably bad to remove uniqueness from a faction in the presences of other viable options.
Option 2 now breaks into several parts (This ratio is going to be hard to decide, but I think it should easily out damage 2 or 3 nans.):
A) Give this vulnerable armor some fighting ship/s
-This would serve to change the fighting dynamics, and create a host of balance problems in Non IC sup vs all IC sup paths (except perhaps scouts but a dedicated scout killing Galv seems strange, and not useful)

Give this vulnerable armor to capital
-Sup is already strong vs a cap game, and this would be limited to a single tech path
C) Give this vulnerable armor to constructors
-This would serve to halt the ability of late game IC to expand vs sup at all (unless uneyed). It would allow for galv to remain a strictly anti base weapon and would mean that while you could not remove IC from the map you could prevent them from pushing into your sectors.
D) Give this vulnerable armor to miners
-It seems that sup may have the most trouble against IC miners. Fighters are unable to get close to IC miners before they can rip. A vulnerability in IC miners vs galv would create a situation where IC literally cannot mine, this is arguably as large a problem as being galved off the map. If one fighter can take down a miner in a matter of seconds(defended or not) IC will be in trouble.
I personally believe option D would create a new and interesting way for SUP to hold its own against IC.