The cost of such boards would tend to play against low cost / easy access objectives.
The screens are bought in significant volumes, and might have been chosen based on suppliers suggesting particularly high-running models they could produce most economically. This might result in custom/private part numbers.
Most design engineers have to build and prototype things that suit their own company goals, there's usually not the luxury of simply copying someone else's design as it either has too many features, or too few, or the wrong ones.
Perhaps build prototypes using parts you can source from places like WaveShare, and then work with LCD suppliers to come up with parts that suit your goals and volumes. DSI with common chipsets and resolutions should help portability and lateral movement.
Perhaps look at some of the MikroE, GHI or NewHaven boards? Or those from other HMI vendors
