When buying hardware in the present age, shop for FOSS software you want to run first. Then, clone the git in full. Finally, use the gource package to create a visual tree video that plays against the commit history. This will show you who is getting their pulls merged, how often, and how they contribute to the project.
What you're looking for is who is consistent, and what they are using for hardware. It will always be obvious on larger projects. They will make little tweaks and changes a bunch between the hardware and software.
You may see stuff like company employees and subcontracting devs come in and make large commits that support some specific hardware, but if you watch carefully, these are only a handful of commits, and then they never return. They likely had a checklist in a contract, completed it, and got paid. They will never return. Likewise, if one of the main devs gets a new device, they will shift to it and you're unlikely to see them make any further commits to the old stuff. The timespan between this transition infers much about the state of the old device support. Maybe just ask them why they switched and what is missing on the old stuff, or just cd to the hardware supporting directory and do $ grep -rin todo or similar types of stuff like code comments or words like hack or need.
Hardware specs and advertising nonsense are worthless and irrelevant. Don't let highway robbers dictate your expectations. The only products that exist are those with FOSS support, so start with the FOSS and ignore everything else as criminal warlords. Who gives a fuck what products and deals the proprietary fascists churn out of Auschwitz or a Palestinian camp.