Solution to using traveler under load??
We used a ss pipe for the self-tending jib on our Soling - which we campaigned in Long Island Sound and as far as Lake Erie - for about six years before finally buying a used ball-bearing traveler. The pipe worked fine, though the ball bearings were better. My father went to a scrap metal yard and secured a length of 2" ss pipe, which he had them bend a little. (It might actually have worked better without bending it, though the idea in the Soling was to be able to maintain the same jibsheet tension and play with the slot width using the traveler. Solings are VERY close-winded, tacking through 70 degrees in some conditions.) He then drilled two holes for what must have been 3/4" ss bolts through the pipe and through the deck where we wanted the pipe mounted. I made some blocks to support the pipe about 4" off the deck and to spread the bolts'' load on the deck a bit. The blocks were also drilled. You could make them out of some scraps of oak or teak - a bit nicer than the 2x4 I used. A ss ring larger than the pipe was slipped over it, and the pieces assembled. A line attatched to the bottom of the ring regulated the amount of travel. The jibsheet was led from the clew through a block shackled to the top of the ring, and then to a turning block on deck near the tack, and then aft. We got some amazed stares from people we beat, but it worked.
You may want something a little beefier for your boat, but for what it costs compared to the "off the shelf" systems, you could afford to experiment with several sizes and perhaps still have enough left over to buy a new jib, too. too.