There is absolutely no sense in converting to 4:4:4 - see from note below why, definitely leave any conversions to the projector
Read this comprehensive article to learn almost everything you might want to know about UHD, including 4K, UHD Blu Ray, wide color gamut, HDR, 4:4:4, 18Gbps
www.acousticfrontiers.com
"There is no intrinsic benefit to the source upsampling to 4:4:4 or converting to RGB. With respect to UHD and HDMI it is actually beneficial if the conversion to 4:2:2, 4:4:4 and RGB is, as much as possible, left to the display, as this reduces the HDMI bandwidth requirements."
if running denon or marantz if you just leave it factory theres nothing to worry about, same with panasonic players - leave to factory setting - select 4k 50/60 with source. oppo also factory setting works just fine. if its apple tv 4k, I have posted my settings (just matching source for rate and range) and that doesnt have any banding going on

this is with jvc though