@hukutka94
There is this option already.
Increased Idle Time
Increases the maximum amount of idle time you can accrue at once by 30 minutes. Unlimited upgrades in 30 minute increments
Current value: 120
As you can see I have +120 mins, so my total idle time is 4 hrs.
@Gussuk
Auto-tech upgrade ... probably not effective except for specific instances where you're smelting/crafting what you need and just need to get through it to get the upgrade.
Auto-draft ... interesting, but unfortunately it'd probably be along the lines of:
L1 - auto-draft every 60 mins, 500 AP
L2 - auto-draft every 55 mins, 50 AP
L3 - auto-draft every 50 mins, 70 AP
L4 - auto-draft every 45 mins, 90 AP
L5 - auto-draft every 40 mins, 110 AP
L6 - auto-draft every 35 mins, 130 AP
L7 - auto-draft every 30 mins, 150 AP
L8 - auto-draft every 25 mins, 170 AP
L9 - auto-draft every 20 mins, 190 AP
L10 - auto-draft every 15 mins, 210 AP
L11 - auto-draft every 10 mins, 230 AP
L12 - auto-draft every 6 mins, 250 AP
So you'd need to invest a bunch of AP before it paid off. Though this could effectively 2x your army camp income so maybe it's worth it?