Hey Roy
Another community member wanting to learn more about device tree might bite.
One of the points Igor and Balbes were trying to make is that cheap TVBoxes are notorious for having inconsistent hardware within the same model. 2 physically identical ones can have grossly different internals.
Common variables, storage chips (emmc or nvram). Network chips.
Pathing could be totally different there for needing to tune delays and other things I don't understand.
TVBox vendors have no incentive to communicate differences or to even aspire for consistency across production runs.
You'll notice that with chip shortages that s lot of SBC vendors had to introduce new models because of changes they had to make. Ex: Orange Pi 3 LTS
A $500 dtb investment and Buying 500 TVboxes vs 500 SBCs from a trusted vendor will likely yield a failed project rather than a project with fantastic cost savings.