The buntline hitch and halyard knots are very compact and cinch up snugly around the becket so they will not adversely affect your maximum car position... if you take a closer look you'll notice the tail section of the eye splice will be significantly longer than the same space the knot uses.View attachment 165245 View attachment 165245 I took a couple of pictures. The first shows the double braid cover that parted, I assume due to friction with the clutch. The second shows the eye splice on the Garhauer traveler car. When the car is moved all the way to starboard, the tail of the splice goes around the sheave in the block. That is why sewing an eye won't work. A knot is fine for a temporary fix, but it seems the only way to get full movement is have an eye-splice.
Another good reason for the knot is to allow you to occasionally rotate the control lines and adjust their length, which will reduce the overall abrasive action on the line from the cleats and clutches.
Finally, the use of clutches on the traveler lines may need to be re considered. This line is one that is used considerably more than a halyard.... on my boat I use the traveler as much or even more than the mainsheet. The act of opening and closing the clutch each time I want to make a minor adjustment is counter productive.... and if you are using the closed position/ clutch effect when tightening it is definitely the cause of your excessive abrasion. My suggestion is to remove the clutch and install a swivel cam(as was in original design)... in a location that allows you to engage/disengage the line with one hand.... preferably from the helm, you can think outside the box a bit here.... but routing the control line back to an open cam cleat at the edge of the cabin top, or nearer to the helm make the device more functional and easier to use.
This example is just one idea of many... but it works well for boats with dodgers.