I think it's not needed.
if you are a shotty build then EE becomes useless!
Well, actually it still gives +2 to accuracy which is the same as for non-shotty builds.
After all (unless on AoSh) you're not limited to shotguns only.
Another thing: define shotty build.Build with shotgun master trait?Then EE is blocked anyway.Build with Shottyman?Then what's the problem of taking EE?
Using shotguns only, taking EE and saying it's useless is basically the same as playing melee and saying Reloader is useless, or for rapid-fire Son of a Gun is useless.
It is true, but that's not a game problem, it's just not all traits are useful for any purpose.Moreover, taking EE with shotty build makes you more proficien in non-shotgun combat.
And the fact that shotguns never miss, but their damage drop with distance is their unique property.I'm probably against this shotgun slug idea.
On top of that, going full shotty build and having a side weapon to fight with makes it very difficult because you will be carrying 2 ammo types and you wont have much accuracy and inventory space unless you heavily mod your ranged weapons.
I believe it is common to have at least two types of ammo anyway.
And since you took shotty build then your shotgun rules.Or at least supposed to.With MAD it rocks.With shottyhead you have juggler(instaswitch ftw), with MFa you can just ignore lots of normally problematic enemies.
Since you have shottyman you also have Rel2, so just blast your enemy with rockets when it's away.Or with BFG.
P.S.Way longer than i intended to write.