Using Drafts to OF3 projects (via Taskpaper tools) — string/number manipulation?

So the basic formatting for creating project templates using Taskpaper and the tools that RO has so kindly provided is pretty easy to work with. I just realized that I have a need to take that a little further. Is it possible to do calculations based on field values?

For example, I have a template for each trip that I take where I define things like Location, Trip Length, and Start Date as placeholders. One of the actions that I’d like to define is “Pack <<Trip Length + 1>> pair of boxers.”

Similarly, it would be great to be able to parse the start date so that I could automagically put due dates on certain things that have to happen prior to leaving for the trip.

Pardon if this seems like a noobish set of questions; I am just barely wading into the placid waters of iOS automation…

Turns out, it was easier to do in Shortcuts than in Drafts. Aside from my normal grumbles about the way shortcuts wants you to join text, it was pretty smooth sailing (although I did write all of the text elements in Drafts, so I guess I could’ve left them there and referenced the Drafts versions for better futureproofing). Hmm, I guess there’s some further to go down this rabbit hole.