this thread is about finding out all of the keycaps needed by all of the special layout 60% boards.
tacticalstache was talking about a software solution that turns the spacebar into a function button when you hold it down. that way, you can buy a normal layout keyboard (the poker 2) and still have cursor keys.
DSA is a keycap profile where EVERY single key is the same height.
for other profiles such as OEM, cherry, DCS, each row is a different height. eg if you put the 'q' key in the 'b' spot, you'll notice it's taller than the 'v' and 'n' keys.
using DSA makes it simpler to replace the weird-sized keys because you can use replacement keys from any other part of the keyboard.