The WebXR version, tested, works. I tested only the Pico (APK)-version yesterday.
Viewing post in Don't forget a Pico(4) version? I offer help for test or build.
Tested a clean project in Godot 4.7.1 stable (Linux). Godot OpenXR Vendors PIugin v5 loaded in asset store. But no vendors-list shows up in Export, Android under OpenXR-select tab. Same with Vendors PIugin v4
Mobile renderer crashes on Pico4, gI_compatibility loads forever like no standalone vendors loaded.
By the way Balloon Dino Death Dome by Kimau Pico4.apk worked.
Downgraded my simple 4.7-project, tested with v4.5.1 and Godot OpenXR Vendors plugin v3: Works. Tested with 4.7.1 and vendors V3: works, but hands (MeshInstances3D boxes) don't move.
Hrm, some very odd results. The v4 and v5 versions of the vendors plugin should definitely work in the editor with Godot 4.7 on Linux... (I built my project with v5 and 4.7 on Linux!) It does sound like there could have been a bug introduced in Godot 4.6 or 4.7 that broke things.
I wish I had access to an original Pico 4, but I've only got the Pico 4 Ultra, and, unfortunately, Pico headsets can't easily be purchased in my country :-(