Anyone have any tricks or tips they can share for how to keep clumps of perlite from falling off of rooted cuttings in cups during up potting? I know the usual of make sure it has a good amount of roots and to make sure it is well watered, but I still manage to loose chunks of unrooted sections of perlite.

This does not sound like it would be a problem, but since I use the cup to make a perfectly fit hole in the new pot, when chunks do fall out upon taking the plant out of the cup, I have to always stop and try to build up a matching area inside the new pot.

This means doing it one handed while I hold the fully leafed out cutting naked in the other hand. It is time consuming and I have to make sure I do not clench down on the naked cutting and force out more perlite. You have to hold it firmly and gently. When you have lots of rooted cuttings to do this with, it takes forever and a day at my slow moving old age. It's the one thing I hate about using 100% perlite.

@drdawg, you use 100% perlite, too. How to you get around it?

So, you are rooting in 100% perlite? And then transferring to a 50/50 mix? I wouldn't be too worried about losing perlite from the roots. Just pot it up and don't bother trying to keep all the perlite on. It's not going to happen no matter how root bound. Perlite is hard and crumbly. As long as it has roots it will be fine.

with Jason but I haven't rooted anything with perlite and @drdawg has been rooting them in perlite.

I agree with Jason. When I remove the rooted plumeria I don't worry at all about how much perlite remains with those roots. Keep in mind that I often root 8-12 cuttings in a single pot of perlite, so I have to separate those cuttings that are rooted from the ones not yet rooted. Doing so generally is going to have those rooted cuttings with little perlite.