You probably meant a portable ARM Linux device; I think it is just difficult to get a team of Linux developers committed to fine-tuning the battery efficiency of the Linux (maybe a specific distro) for the tablet, so I am not hopeful about having an excellent battery life, as much as I would want it to happen.
No, that’s behaving as intended, and as the issue text describes. Look at the edit history of https://github.com/webcompat/web-bugs/issues/99713 to see the most recent example of a webcompat-bot issue that started in that shape, and was accepted, and so then its content was put in.
"A web browser reference implementation using Mozilla Android Components.
The Reference Browser is not a product intended to ship to end users. Instead it is a Technology Preview for many new mobile components that multiple teams at Mozilla are currently working on
It includes the Mozilla Web Platform via GeckoView, a new modern Firefox Accounts and Cloud Sync implementation and the new "Glean" telemetry library. All these components will be foundational for Mozilla's existing and upcoming Android products.
The Reference Browser can also be a starting point for your own new browser-like applications. It depends heavily on the Android Components project where most of the actual implementation lives. That project also includes many smaller sample applications."