I'm still using a Photon Q running LOS 14.1 (Feb 2020 security patch) and microG on a daily basis. You've to avoid gapps, decreases performance considerably. Much faster compared to Droid 4, still somehow sluggish, but sufficient for my requirements: phone/SMS, email, whatsapp/signal, webbrowsing with opera, ebook reading with moonreader, even navigation with sygic works pretty well, as well as vnc to fiddle with a raspberrypi. Of course you have to forget the camera and gaming (both I don't really need).
Still hoping/waiting for an affordable Pro1...