Sorry, I meant "the only built-in option for messaging between Android and iOS." A lot of people don't want to install any third-party messaging apps.
LinuxSBC
Metal doesn't work with wireless charging. Plastic feels cheaper. Still, many companies are making plastic phones, and I'm sure some are making metal ones as well.
It still has issues, but it's much better than SMS, which is currently the only option for messaging between Android and iOS.
Heat difference is what you can get energy from, not heat itself. You need something cold to get energy from the heat.
Luckily, pretty much any modern x86 CPU works about as well as any other. I've had a Ryzen CPU for about three years and an Intel CPU before that, and I notice no differences (apart from obviously the faster CPU being faster).
A .ovh domain is more like $3 a year. That's what I'm using.
EMS doesn't support bridges unless you pay for the highest tier, but the list you linked is good.
When performing a gesture, the animation on screen matches up to the motion of your fingers. Stopping moving your fingers halfway will stop the animation halfway, and moving slowly will slow the animation.
Wayland. It generally works a bit better at this point, and it will only continue improving while X11 falls behind. I occasionally need to switch back to X.org for some legacy screen-casting or remote desktop apps, but even the ones that support Linux as an afterthought are starting to add beta Wayland support.
The only window is Firefox, which makes it hard to tell, but I'd guess it's GNOME with the Aylur extension.