In no particular order, a few additional observations about the GPD Pocket 2:
The battery life of my GPD Pocket 2 (Ubuntu MATE) definitely is shorter than my Pocket’s (running Linux Mint). I have not run either of them down to zero percent, but (assuming the battery indicator is equally accurate on both), my remaining charge after about 4 hours of writing, coding and web browsing is ~70% on the Pocket vs ~50% on the Pocket 2. This is perfectly serviceable for me, but if you rely on true all-day battery life with your original GPD Pocket, you may want to pack a charger or battery.
On the flipside, the Pocket 2 is much better at conserving charge when asleep, losingabout 1% charge for every 2 hours (the original Pocket would not truly sleep but only switch to a lower power state, and usually deplete its battery in a day or so of standby.
The Pocket 2 also charges considerably faster than the original. I never accurately measured how long the Pocket takes to charge from 0-100%, but it was slow enough that I developed the habit of charging it over night whenever it had less than 50-60% left. The Pocket 2 charges from ~50% to full charge in less than 2 hours (on the provided charger - I have not tried other chargers).
As for portable batteries, not all will charge the Pocket 2. Specifically, it appears that 1A is insufficient. However, USB-C PD is not required to charge the Pocket 2. I own two Anker batteries: a PowerCore 5000 (5V/2A) and a PowerCore Mini (5V/1A). The former (with a Micro-USB-to-USB-C adapter), works, he latter doesn’t - the power LED flashes as though receiving a charge, but the battery percentage does not change and the battery icon does not indicate a charging state. I left the PowerCore Mini connected for 10 minutes while the Pocket 2 was asleep - in all fairness, it’s possible that the battery may have charged (very slowly) if the machine had been entirely turned off or if I had waited longer. Maybe I will test this some time.
The tearing issue I described in my previous post affects other applications beside web browsers too, to varying extent (less obvious than with web content). This is more of an annoyance - it does not hinder usability much - but it bugs me. I have posted to the GPD Pocket subreddit, and received some suggestions to troubleshoot this, but none have had any marked effect. Maybe I’ll try a different Linux distro (with a different display-manager) at some point, though I’m otherwise fairly happy with MATE, and don’t partiularly enjoy setting up a computer from scratch.
Another weird bug I have found: I can consistently make the display manager crash (sometimes to the login prompt, mostly to a black screen - with a blinking text cursor but no way to actually input commands) if I tap OR click on an menu bar icon (e.g. the battery percentage) to bring up a dropdown menu, then (while the dropdown is visible) tap (NOT click) on certain application windows (e.g. Firefox, but not VS Code or MATE Terminal).