if you have anything above 99 or below 1 ire, use rgb effect or levels to get within that target ire before using lumetri. then use its black and shadow slider as pedestal. i find enabling hdr in lumetri gives 10x more control in shadows recovery.
can you explain traditional gamma? there are curves but they are controlled as output after basic tab. you need another instance of lumetri if you are going to layer its parts out of order. weird, I know.