My personal take is this: “if you already have a device that doesn’t have a build available for it, then maybe the GSI will be minimally viable to extend its life instead of binning it, but it isn’t a good option to buy a device for use with iodéOS that doesn’t have a proper build available for it.”
There may be firmware compatibility issues with a GSI build depending on the device, from telephony issues, camera issues, battery optimization, etc., which is why we maintain a list of what is working and what isn’t. I’ll discuss with the team how we may want to clarify some of this on our documentation,