The PSPi Zero Version 5 GitHub got some updates. The driver got a bunch of optimizations, and some new features such as a (somewhat experimental) "sleep mode".
https://github.com/othermod/PSPi-Zero-Version-5
There is also a ready-to-use SD image for those of you wanting to avoid copying files and running scripts. It was made yesterday, and it includes the most recent driver already installed on a stock RetroPie v4.7.1 image.
Google Drive link: https://drive.google.com/file/d/1LdgOSTCEvPwvksIEMmHCxauEN8INBU-z/view?usp=sharing
Torrent Link:
https://othermod.com/wp-content/uploads/PSPi-Zero-v5-8.17.21.7z.torrent
The PSPi boards are back in stock.
https://othermod.com/product/pspi-zero/
If you miss this one and want a notification for the next batch, you can subscribe to get an email notification on the product page