Using LUTs as FX6 Base Looks

[videosoul]

Regarding making one's own LUTs for FX6 Base Looks, on this guide by @alisterchapman it says:

"For the best results you will want to use 33x LUTs, and the LUT should be designed for full/data range In and with full/data range Out."

Is that correct?

Surely rec709 is typically legal/video levels, whilst slog3/sgamut3(.cine) is full/data levels? Typically, I would have thought that most LUTs will be bringing the image into the realms of rec709... so therefore surely they should be full/data in, but legal/video out?

Or is the the idea here to preserve superwhites to 109%... and in LUTCalc, that is referenced, isn't that done by turning the Hard Clip setting off or to "Unclipped"?