Mac OS 10.14.6 running version 9 of KM.
I've added a piece of software named Across (acrosscenter.com) that is essentially a KVM bluetooth app. The hotkey command to switch keyboard and mouse between computers has four options in the Across menu: left and right control, command, option or shift (i.e. pressing both the left and right of each key at same time). I haven't been able to figure out how to get KM to do that yet. Any ideas?