I'd suggest the plastic "cone thread adapters" for each spool pin.
Thread nets on each cone will keep the thread unwinding right so you don't have waves. You just slide them on the spool of thread & have the thread coming out the top.
Check with your local sewing store. They should carry both items. I use the large spools on my serger all the time & have never had any flop off. I do the same with my coverstitch machine.