Thanks, Murph, for the suggestion. I do sometimes use organs that are at 48 kHz 24 bit, but maybe I could use one of the headphone outs to make up for it. It sure is reasonably priced.
Ed, yes, my eventual plan is to go to a Mac Mini, but my 2013 MacBook Pro shouldn't have any of those audio issues of the 2018/19 MacBooks. My guess is that your 2012 Mac Mini probably has the same generation Core i5 I have (or an i7, probably with 4 cores instead of my 2). Before all these audio issues, the computer seemed to be doing just fine, which is why I am tempted to blame all of it on the Cymatic. Hence why I started the thread asking for recommendations on interfaces... I've just been overwhelmed looking at the higher-end options