When Hobie was supplying charter boats for the nationals we had as many as 24 boats to put together, lace up and the whole enchilada.
CABB Commodore, John McKnight, had a tool he made just for tightening up laces.
He took a flat piece of aluminum (About 18" long) and mounted a cam cleat near the end of it, then cut out a hand hold on the other end and padded it.
Then just grab the rope and pull from the side of the hull. It worked really well.
Otherwise, I find it pretty easy to just use vice grips.., one to pull the line tight, the other to hold it there while you grabbed the next loop. Less sophisticated, but it works well.
Good luck
Rick