First off, how could I not like the concept of writing for an audience of one? Of course this makes my own comments superfluous, but, as you wrote, the whole exercise is an indulgence, anyway, so indulge me, too, please.
I admire the idea of putting the output together from single words, but I do believe that your comment on the legibility of the source code for non-programmers is a bit overoptimistic. Usually, Inform code is indeed much easier to read than it is to write, but this (Vorple + Tracery) is a special case that is more likely to scorch the unsuspecting, hopeful visitor lured in by your promise of intelligible mechanics and implementation. This is nitpicking, though: of course only swots would look at the source code.
What struck me with Scents and Semiosis is that for my tastes (irrelevant as they are), the mechanics are kind of backwards. I would suspect someone sensitive to olfactory impressions to associate a generic smell with a concrete memory instead of a concrete smell with a generic feeling. Given the way it works here, it seems questionable why the protagonist would even need to open the bottles. The result is abstraction, which, while it is certainly a way of assigning meaning to symbols, disjoints the various components of the finished perfume in my mind, instead of unifying them to a narrative about the protagonist's past. That might be my own preference, but this kind of fundamental critique is not overly helpful. It also doesn't mean I didn't enjoy your work. I very much did.