Now I'm no Galio main, but I found something that might help.
Galio, as about 3 people are aware, is a champion.
"A champion!?" you ask.
Yes. He exists.
Now, I could call myself a Galio main (as I have raked in approximately 1 game as Galio support in a normal blind pick - we lost), but I would prefer to take the modest approach and claim Galio aficionado.
Now to the meat
of the post: what do I think could help Galio?
Well for starters: a rework. But let's not go there, because for all we know a rework is on its way, or coming in 2019.
So as one thing that could help quite a bit: make his auto attacks ranged. He can be such a pain in the butt to try to last hit, and I end up having to waste mana on my W any time I want to last hit a minion, just in case the opposing laner wants to trade. It really doesn't feel beneficial to have to use an ability every time I want to last hit. Sure, his waveclear is great, but at level 4 when you're just on the brink of being able to full clear a wave, but the enemy pantheon can now deal tons of damage
I don't WANT to have to auto 4 minions and waste mana on my W just to do it.
"But SPARKKY, it wouldn't fit THEMATICALLY".
Bite me
Heimerdinger has an infinite number of wrenches he can throw at people, when he's a genius inventor that could just build a god damn gun.
I understand making a champion start to deal ranged attacks instead of melee could be hard to do (or easy, I really have no idea), but it would sure take a lot less time than a full blown rework, and it might give him some more power in solo lanes.
Hell, he might even see some play.