Interesting approach, so far I did not think of such a use case for ActivityDiary. - I had in mind more a tracking what the user did than a planning app how and where to use it.

Can you create a ticket on github for this proposal to ensure it is not lost? - It is great that you contribute here on utopian.io but the development of the project is handled on github. I try to follow up also some discussion here, but you can only ensure that your contribution is not lost if you place a github ticket. And do not forget to cross-link the ticket from your contribution from here.