I think the magnetics should be fine. The keyboard controller can filter out the (predictable) noise from the fan, and the lid sensor shouldn’t be that sensitive.
The bigger problem I see is the keyboard thickness. From the top of the key to the bottom of the backlight pcb is 3.8 mm according to Is, or will there be, room for an ultra-low-profile mechanical full-size keyboard and a Sensel touchpad? - #2 by dosssman
So a screen + pcb + magnets might be too thick.
And maybe the laptop version should use an e-ink screen, to save battery power.