Multiple Video Sizes

I most post/sell time-lapse sequences. I use to only upload 4K (3840x2160) I now have the ability to shoot and export 6K (6144x3160). My question is, now that I can upload 6K files, do I need to also keep exporting and uploading 4K UHD files? Does pond5 automatically create 4K Cinema (4096x2160) out of the 6K file? I mostly ask because 4K UHD is a different aspect ratio than 4K Cinema and 6K are. So for a single time-lapse, should I upload 3 individual files, one 6K, one 4K Cin and one 4K UHD file? Or Just the 6K file? Or the 6K file and a 4K UHD File?