First, let me clarify something.
Roundtable Staff are NOT Commissioners. They are STAFF, hence the name Roundtable Staff. They earn the Scouter's Training Award for Roundtable Staff. The Roundtable Commissioners earn the Arrowhead Honor award, then the Scouter's Key for Roundtable Commissioners. If a Commissioner earns these two awards and serves in a Commissioner position for 5 consecutive years, then the Council can present that Commissioner with the Distinquished Commissioner Service Award.
The DCSA may be earned more than once, but no device pin is to be worn on the square knot. Device pins are shown for the area that the square knot is earned (Cubbing, Scouting, Sea Scouting, Exploring, etc.)