Having only gems to quickly finish an upgrade or training feels very one sided, I get the game needs money but the gem cost for most things only gets more and more ridiculous as you lvl there should be ways to lessen that strain on the wallet and nerves
Love this idea, instead of useless S1 Harvesters, they could put items like this on the POV for example.
Taking a couple of hours off, could come really clutch when you have a building that will finish in a time frame where you wont be able to chain another building for several hours.