Customised trigger (i.e. <^>) for due date (not <.>) to avoid clashes with decimal durations

I want to be able to schedule an event or task and have its duration be 1.5h or 2.5h, but the full stop triggers the due date suggester. I can press esc after I type <.> but this slows down the process of quickadding events and tasks and I would have to escape after the full stop every time I add a duration with a decimal in it.

There are plenty of lesser used characters, <^> being one of them that could be used for due dates instead – if this disturbs pre-existing habits, then maybe customised triggers could be implemented?