thinking of building a mainboard with upgradeable ram, storage, CPU and GPU,
But I don’t have the capabilities to do so.
Desktop components usually take up a lot more power than laptop components and in turn draw a lot more heat. It would be quite difficult to achieve this with the profile of the Framework 13 and even with the Framework 16 it would be quite difficult.
While this has been somewhat achieved by devices such as the Alienware Area 51m, they clearly did not last very long (as in the product line not the laptop itself).
Unfortunately though, when using laptop components, parts like the CPU have to be soldered onto the mainboard. Framework has gone a step further though by making the dGPU in the Framework 16 separate which allows for more upgradeability.
What do you want to do that not already exists as mini ITX?