It seems like fixture blocks could be more versatile with radiuses,
A one pin fixture block with a single .5" radius could be easily used as a single point of contact while still leaving you with 2 full 1" faces for clamping when used otherwise, 2 radiuses (half round) could make for easy clamping on one face with a single point of contact.
On larger/longer blocks (i assume) most people aren’t going to be using the 1" faces for much if any clamping, rounding those corners would trade that ability for clearance that might be handy, say inside a corner with a fillet weld.
Obviously this would be a slight bonus at best and would come with some trade offs but i appreciate the thought that goes into Fireball products and thought i might float out a thought of my own