Jules I usually dont go for it too early in the game. I did this time due to the resource abundance but its not a priority early game.
I find getting Irrigation, habitation, commerce and even SB's are generally more important, its more of a Mid game tech if anything.
136 hours is a lot of lost time for your economy techs and thats what gnomes are about. Need the money to buy the resources, need the resources to make the weapons, need to stockpile the weapons to be able to fight continuously.
I DO however like your Idea of a second sling tech possibly hidden behind explosive powder....
And I am noticing a theme with your posts, you say Elves need a boost, gnomes need a boost. I feel if anything knock humans down end game, they seem to be the problem late game.
Charge through Shieldlines, Gate to overcome Gnomish forces, Eat Elves like Filet minion, Orc's can be a problem but nothing they cant handle with Light armor maxed.
