Rhino 6 for Mac allows launching with command-line parameters like -nosplash or modelname.3dm …even -runscript …see: Launching Rhino for Mac with a runscript argument.
I can imagine you could either write a bash script to do this or perhaps even use some combination of Rhino’s macros _Open,_Close, etc. to do this.
I’d be curious to hear where you hit snags.
Note: this was not possible in Rhino 5 for Mac.