Perhaps a speedup option. Or maybe incremental scaling of buildings to prevent spamming being an option that always works. multi select and mass upgrade features would help reduce the clicks required for large-scale production.
I second the request for mass-upgrade. After just a few portals, gameplay becomes more tedious than fun.
And how about click-and-drag to “paint” as many of the selected purchase as you can afford? Like painting a whole line of chargers along a portal.
Although I suppose there’s little chance of coming back to this game after five years now.