It would probably be OK for the occasional trip through the cleat if you do an end for end splice like that. Note, however, that I was not happy with the Marlow Excel Control (I bought it for a downhaul line originally). It seems to chafe pretty quickly and although it has high modulous fibers in the cover, it is STRETCHY because the core is fuzzy polyester that compresses. I'm sure that fuzzy core makes that end for end splice easier, though.

Regardless, you are going to be relying heavily on the whipping whatever you do...whip it with a strongly colored thread so you can at least identify it as it starts to get into the purchase system. I would still try to avoid carrying it through the heavily loaded purchase section.

Note; we had that Excel control on a continous furler line on Alan's Mosquito trimaran and it worked magically for that and the end-for-end splice held up to a good bit of tugging.

One other note; getting the core through the cover on the Robline Dingy Control takes a lot of patience because the cover is so tightly woven. I would prepare at least a 6 pack for this splicing job if you are going to extract the core out of that line!