The SKR pico is working nicely now in my Ender 3 with a new custom front enclosure. There's a few issues, however, that make me say that it isn't perfect:
* The single biggest problem I had is that the motor pinout in the schematic on Github is wrong. It's labelled 2B-1B-1A-2A but is actually 1A-1B-2A-2B. This matches Creality's (and most other vendor's) wiring, but as someone who carefully reads both the TMC datasheet and the schematic diagram, this really caught me up.
* The UART cable for the rpi is a bit short. Also, the photo shows it plugged in opposite the actual plug connectors (e.g. the JST is plugged into the Pi not the Pico for whatever reason).
Otherwise, my experience installing and putting the SKR Pico into service was excellent. Something I would generally suggest to other users is to flash Klipper using SWD from the Pi (requiring an additional three wires be connected) instead of by the bootloader, which once installed is faster, easier, and more reliable.