I read such a feature request, but it was closed and so I could not comment on it. Instead the feedback tool asked me to create a new task - so here goes:

In the quick-add input box the '^' char can be used as a short-cut to enter a "Start on" for my about-to-be-added-task. Valid input after the '^'-char is Today/Next/Tomorrow/Someday/Waiting or a date in some localized format with or without the year. This probably covers most use-cases, but I find myself often wanting to add a task for next week (i.e. start on monday).

But you can't say "Start on Monday". If you want a task to start on monday, first you must find a calendar and look-up what date it is on monday and then you can enter that date. Or, alternatively, you just skip this part of the quick-add and edit the task after it has been created. None of these two solutions are very productive. It shouldn't be too hard to support named days, I'm sure there are plenty of ready-to-go-drop-in solutions for this all over the place with public license for you to integrate.

There, looking forward to this new feature that will make my work so much easier.

(and for reference to the other similar request, I don't agree that specifying a day would impose a due-date and put the task in the inbox. That sounds like a weird use-case to me. The ^ is clearly defined as 'start on', and whatever you choose should transfer the task to that "Focus" group. Perhaps there should be a shortcut for the due-date as well but that will be another feature request)