[ ] e.g. separate "normal channels" from "template channels" (I really like the name, compared to "abstract channel" - that's what you get from programming on JVM :joy: )
[ ] Once Channel Layout is done: look at example channel_layout_test fixture with "missing_break_in_geometry_reference". In a Geometry Reference, it misses a DMX Break for Break 2. It's not clear what should happen to me now, but there should definitely be a problem. (What did glowdtf do?)