On V12, it isn't possible to remove the field titles as you could in V11 to allow the space in which fields take to be compressed on screen. The issue is that in V11 it was possible to remove titles from fields allowing more fields to be displayed in the same space and now in V12 you are not able to and so fewer fields can be displayed in the same space. Please see screenshots below.
Guest
Implemented through the "Stacked" attribute of a screen or block.
