Today we conquered the round vent. This guy is tricky and uses the copy Fluent mesh to make an inner piece that you slice. and not the other way around. The vents are positives of the negative slice array. Its the opposite way of thinking about it but Discord linked me to a handy little video from CG Seb.
https://twitter.com/CGSebSciFi/status/1505138306643857411
Totally makes sense.