Pretty sure it’s only superficial, this is the photo I sent framework support of the inside of the bottom cover (under the right speaker) in the same place the worst crack is on the outside, there is no visible deformation at all, even when I tried to put a lot of pressure on the screw using a screwdriver, the crack is hidden under that corner metal piece.
Also support has gotten back to me and they say they’re going to be replacing my whole core laptop? I’m pretty confused about that since there seem to be people more in need of replacing the whole laptop than me 
mine is totally fine apart from the cracks and some misalignment on the trackpad, and it’s usable with those defects.
EDIT: they got back to me with an explanation. makes sense they want a full sample of the issue instead of spare parts.
We’ve decided to take the whole laptop and not send out parts instead due to possible
further investigation for quality and improvement purposes, since this is one of the earliest reports of the variant with this issue.