Unless you are going full res, which it sounds like you can’t…then why bother?
“Client wants to work in UHD” why? Are you pulling a bunch of keys?…then you might want highest res possible.
If it is simply so you can say you did….well big whoop.
work in HD, transcode to something easy to work with.
uprez to UHD for final delivery. What does the client care what resolution the offline takes place in.
I’d much rather my editor work at a low res, have their box be efficient and snappy, and then give me the best quality outputs at the end than worry about what resolution they cut the offline in.
(Tell em its UHD and proceed :))
Glenn