I'd take a serious look at Racebred. They don't have an E92 pre-cut kit yet, but can do it custom for you.
https://racebredcomponents.com/produ...20452540907618
Otherwise, have my buddy Brian do some analysis and maybe a custom design for you:
https://www.yetiracecraft.com/aero
(full disclosure, he's a friend and I've already hired him to do a custom front splitter for my C7 since I don't like any of the pre-built stuff)