It was pretty exciting when Adafruit came out with the Trinket M0 board. Previous generations of Trinkets had been used in quite a few Cedar Grove projects mostly for those that needed just a few I/O pins and that would benefit from the board's tiny footprint. The M0 version had the same footprint and economic pinout, but also promised to free the coding task from slaving over an IDE to a simpler interpretive language and development process. At the time, the language was MicroPython. That was enough of a reason to convert some of the old projects and to put a bunch of Trinket M0s in the inventory for future projects. Adafruit adopted MicroPython and quickly focused it on a library-robust version, CircuitPython. The transition to CircuitPython made it even easier to develop projects.
The Trinket M0 shared its internal memory between what was needed for CircuitPython code execution and the thumbdrive-like USB storage used for source code and libraries. It became apparent that the Trinket M0's memory capacity would be unable to keep up as CircuitPython device libraries matured. Although there were Trinket M0s still in the workshop's inventory pool, Cedar Grove projects moved on to Feather M0 and M4 Express boards with the added memory capacity to dedicate to USB drive storage. The M4 boards were faster, too.
The objective of the RoverWing was solely to repurpose Cedar Grove's idle Trinket M0 inventory for projects that didn't use a bunch of I/O pins, didn't make extensive use of CircuitPython libraries, and that needed to connect to the workshop's growing inventory of FeatherWing boards. LiPo battery management was added to the RoverWing just in case a project required portability.
Hmmm. There are still some Trinket M0s left in the workshop inventory cabinet.