I own a GPD max 2 and a GPD win mini and both are really not suitable for my workflow: the battery life is not as good as an iPhone and the fan keep screaming. Maybe I should try installing linux on them. Now they are just gaming devices and a backup machine in case I really need to open office documents.

OTOH I have used my iPhone pro max for development for a long long time. The trick is to use a always-on linux VPS pairing with many excellent terminal emulators on iPhone (e.g. blink.sh).

Essentially I'm using iPhone as a thin client to visit a true linux development machine, and both of them play their roles perfectly. While other solutions while trying to be both roles with a single device failed miserably.