I hear it reported that the Re-registration workaround works for some, and not for others. Or works for a while, then not.
I will presume that (for those experiencing ANY slowness) people are first clicking the
Update Registration button EVERY time they start RDSS, and when they first start it - before moving on to handicapping.
When it works fine for a while, then resumes being sluggish, close RDSS, restart it, re-register it, then resume your work.
I know, not satisfying! Short of waving a magic wand (mine's in the shop

), I have no other workarounds to suggest at the moment. I am sorry.
As mentioned earlier, working on an update as fast as I can ...
Ted