[quote='818568021, rsfinn_halcyon, /thread/818568, /profile/rsfinn_halcyon'] I wanted to confirm that this is the current best practice. [/quote] For an ES sysex, yes. As to what happens when you combine ES and NE, I did some digging and that text is definitely present in the Xcode 12.5 man page and definitely gone in the Xcode 13 one. Based on that info I was able to track down FB8701548, which was a developer request that we remove that limit. This was resolved in macOS 11 and, as part of that, we removed that text from the man page. Neat! With that in mind, let’s return to your other questions: [quote='818568021, rsfinn_halcyon, /thread/818568, /profile/rsfinn_halcyon'] should they each declare the Mach service name under their respective Info.plist keys? [/quote] That’s up to you. I can see arguments either way: If the ES and NE subsystems within your sysex are tightly bound together, it’d make sense to use a single named endpoint. OTOH, if those subsystems act independently, it’d make sense to have two d