Finished printing.

Angle of pop through was too vertical now.

Conical spring was too tall now.

Base lip was too small to take the force and stretched.

I'm thinking I'm going to make individual buttons and sew/bond them to some fabric backed vinyl instead of printing a sheet of them. Printing a sheet would consume a lot of TPU for not a lot of gain. Also means I can decide on a layout later.

Adjusted. Printing again..

Edit: Pop was still too vertical and conical spring was too low now. Printing again..