According to the Framework CEO on the Linus Tech Tips video about this thing [1], they tried and AMD assigned an engineer on getting modular memory to work and decided it's not possible.
Unless there's another company out there shipping this CPU with replaceable memory, I'll believe them. Even with LPCAMM, physics just doesn't work out.
Of course, there are plenty of slower desktops you can buy where all the memory can be swapped out. If you want a repairable desktop like that, you're not stuck with Framework in the same way you would be with laptops. You'll probably struggle to get the same memory bandwidth to make full use of AMD's chips, though.
there isn't. This thing was designed the same way apple designed their unified memory. This thing is meant to work hand in hand with it's iGPU.