Exporting and keeping Log S color/gamma look?

Hello-

Export question.

Been exporting 1080 29.97 footage - primarily Log C shot C300 & Long S shot F5/Fs7/F55, then consolidated in Avid - for our motion graphics guy to build graphics from. Footage will be full frame and relatively unmediated in his graphics. Goal is to deliver uncolor-corrected HD res level exports that function more or less as the master media, ie we don't want to re-conform/matchback his work later in online/finish. 

Per his recc, I've been exporting ProRes 444 HQ (color space is overkill I'm guessing given our footage) and generally those exports' color looking pretty close to the originals in Avid. But for some footage - esp our S log stuff - exports definitely look more visually punched up. More saturated color, higher contrast. Doesn't seem to be any hidden frame flex color correct on these. Maybe I'm not understanding how Log S works. 

Any recc.s for an HD codec that will best maintain original color across these var camera formats? Important bec/ in all likelihood our colorist will want to do his own pass on the motion graphics work. And again, don't want to matchback. It's a LOT of very short shots.

Thanks in advance, Nick.