The split is only set on the score and applies to parts as far as I understand it; here it’s set at the start of bar 5. So in my drum part I would want a single bar repeat then a consolidated 6 bar repeat on the next line. Because it’s consolidating through the split, I can’t split in the part for a system break to ensure everything is in sensible four or eight bar systems.
OK, so I was a bit confused with this as the Split Multi Bar Rests only appears in engrave mode where you can’t have a carat; but your suggestion achieves what I need. Thanks!