Check out The Sky X, which isn’t cheap but it offers the same level of automation as SGP.
Also check out the Cloudmakers.eu apps. You’ll need to install a local Astrometry.net instance and the last time I checked, it’s not the same level of automation as SGP, but they have a nice set of Mac Astro imaging apps.
You could also check out AstroBerry server (RaspberryPi) and run EKOS and KStars on your Mac as client apps. You can come close to what you’re accustomed to with SGP for very little money by comparison.
You might be better off running SGP on another mini PC riding on your second scope.
I have come to realize that I’m very spoiled with plate solving, auto focus, and automation in SGP.