Dear Timmy,
There are at least 3 ways how to play multiple cues in BEYOND, initiated by DMX. The first way is QuickShow style DMX IN, configurable from DMX settings tab. This method can start one cue, because we have have one channel for Cue, and need to have understandable method to stop the cue playback. The second direction is ProTracks and scripting. ProTrack is a cue player, what makes easy to organize multi cue playback because you have access to multiple static cue players. The third direction, and main direction - "DMX Server", where each Projection zone act like a DMX fixture, with own DMX address, cue/page, and so on. If you want to play multiple cues then you I would recommend to use DMX Server.
Why not the grid... grid made from mouse, "event" based control, like mouse and keyboards. DMX is state oriented control, where one DMX packet represent the state, Your idea of multi cue, or groups is understandable, but at the same time - incomplete. We can discuss more, however, independently on results, BEYOND already have 3 different methods, and adding 4th method, that will be problematic, does not seems right. At the end, multi cue playback is a question of the control of multiple players. BEYOND has 3 player pools - dynamic pool for grid, ProTrack, and DMX Server (where each zone has cue player). So, BEYOND already has dedicated solution, specially designed for DMX. Why specially? because this is another type of final state machine.
You should be able to find PDF about DMX Server in Help section of main menu.
Best Regards,
Alexey