Yes, the proper tensioning of the rigging wire is a bit more complex and
critical in a keel stepped mast than a deck stepped one. Everything can be
quite loose in a deck stepped mast and the mast will be perfectly well
supported since it will just rotate about its step. Insufficient tension in
a keel stepped mast can introduce a bend just above the deck/cabin top
partners. This bend can contribute to column instability.

In practice, there won't be significant difference in wire tension between
the two rig types but the deck stepped is more tolerant of under tensioning
of the wires as long as the tension relationship between the uppers and
lowers is right.

--
Roger Long