I too had issues with this supplier, as I purchased two identical adapters yet I received different connectors on each.
I thought they had a minor mishap at the warehouse where they added two different products on accident, but now they seem to be shipping whatever happens to be in reach.
If your cable gets caught in the fw16 I recommend you tape it to the m.2 board and install it using a regular m.2 screw. As the one mount screw in the m.2 module is too small.
Bending the board shouldn’t be an issues since it doesn’t have any components on it.
Also when 3d printing I used PETG filament. It is more flexible than PLA so it doesn’t break when bending it into the slot.