I haven't done a ton of usage outdoors, but my boox max lumi works for this. IIUC the android it runs is "unlocked" so I think you could use it as a computer if

I haven't done a ton of usage outdoors, but my boox max lumi works for this. IIUC the android it runs is "unlocked" so I think you could use it as a computer if you wanted. I use it as a tablet and a monitor.