The helpful comments on that post gave alternatives including just using the 'caffeinate' command from Terminal and forms of automation such as Alfred.
While doing a bit of digging I came across the little tool "iCanHazShortcut" which lets you assign keyboard shortcuts to anything that can be run from Terminal.
Goodbye Amphetamine, hello ICHS!
I now have:
⌥ + ⌘ + = for:
caffeinate -dt 3600
⌥ + ⌘ + ← for:
It's more flexible and I don't need to have the icon in the menu bar.