Hi Marty and welcome to this Forum.
Shame about the RSM, it is a constant menace, much worse in my opinion than mealy bug because you always see the result too late. All you can do is to stop them doing even worse. But with the clumping species you've mentioned above, it might be worth giving them a good anti-RSM treatment and try to keep them. I know that I have seen some plants that I've had attacked send out new offsets, even if the growing point of the original plant is just too far gone. Then after a year or so, cut it off and re-root. It may not be worth doing this with every plant, if they are easy to obtain, but if it has been a treasured posession,or a form that isn;t readily available again, then why not try at least.
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Chris43, moderator