I've spent a lot of effort on developing advanced functionality for Pibow/Multibow, such as asynchronous key handling, key sequence chaining, timers, multiple overlays, unit tests for all this stuff, et cetera.
The advanced asynchronous functionality requires changes in the base Pibow firmware. Pimoroni initially provided a low-level function timer tick on a separate code branch (without a release), on which I then built a lot of advanced functionality.
However, many months later, and after several fruitless attempts to get some reaction from Pimoroni, there is no visible activity to release the low-level timer tick function I need for Multibow as part of the ordinary Pibow firmware releases.
Since I don't have the resources to maintain my own fork of the Pibow software and are a believing in the principle of "upstream first", this is the end of my Multibow project.
For reference: Pibow Issue #15: Timer Support?