It's been 5 years since I created this tool, and the chance of adding the new feature you described is low, because not many others requested it, also because "setting due time" via the Google API just never got the support from google. So, maybe this tool is great working for you at this moment, but sooner or later when you need to set a due time, it'll become useless. Meanwhile I recommend
https://calendar.google.com/calendar/u/0/r/tasks as an alternative. It has no keyboard shortcut, but at least it's officially made by google.