Most people use blank DSA from Signature Plastics on EDox. Other type of keycap may indeed be much more challenging, especially sculpted keycaps that are different shape on each letter row like most keyboard have. Also depending on desired layout, legended keys may be improbable to impossible. For the most part, you can always work around limitations if you are a little flexible.
We don't know "for sure" what most people use on Egdx.. because it was designed to be a highly adaptive platform..
But..... I don't use DSA myself for the main keys.. I use the imsto blank pbt. The stem is smoother than the original kbc pbts.
DSA surface area is 40% less than DCS/CHERRY/OEM
with DCS it's much easier to hit the keys.
IDK why any Egdx owners would want printed caps on the ergodox.. it's just silly...
The Egdx allows 0 jump/lift key access, there's absolutely NEVER a need to look down..
Everything is accessible by single finger pivot.
Higher accuracy is much more achievable on the Egdx.
Now, if you're after the aesthetic factor of label caps... yea.. i get it... but... the EGDX will change the way you look at keyboards forever..
You will see it as a sharp tool... pretty be damned...