Gizmo , the European yachts have had no rowlock for 10 years +.
with the centre sheeting they dont seem to need them .
without them you can push the boom forward to belly the sail when accelerating.BUT you then need to push the back of the boom in to stop the clew ? from getting on the windward side.
In Argentina I would have given up one of the kids , to get a plastic rowlock on the front of my boom.. I still use them , but when fully sheeted the front of the rowlock just sits on the middle of the mast

like this.
there is no pressure on the mast at all , like we had in the olden days

The original blokart had a metal U fixed to the boom with a webbing strap that
fitted against the mast The webbing was sewn with pockets to fit over the jaws of the U
They may have changed this now

A couple of years ago a few of us tried a swivelling gooseneck that swung
about 45 degrees from side to side
I couldnt see any advantage to it and took it off I dont think anyone else has it on a 5 here either