I’d be really interested in an analysis of tau in light of this discovery. Would tau fit more naturally here than pi, as it does in other examples?

The construction so far uses ln(-1) to get to pi - so far no easy way to tau.

So, to follow up I'd say in the context of EML I think ln(-1) = pi*i is the natural fit. Pi and Tau are both more advanced constructs.

I'm working on queueio (https://github.com/ryanhiebert/queueio), a background task runner for python that uses asyc function to communicate with the queueing system, but encourages using regular synchronous and blocking code for the actual work.

It fits the bill for me where function coloring provides something truly useful that you can't get without threading. Using Celery canvas to compose signatures is a great step, but the added power of being able to compose them in a more standard code flow is the killer feature that I wanted bad enough to write it myself.