Trade is not terrible, but no chance AVs accept.
Byram is potentially a franchise DMan. Position and age of this type of player is not normally moved unless the return is significant ie. Seth Jones vs RJ.
Caufield is small and one dimensional and comparable to being the next Debrincat. It’s not a knock against, but positioning of being a Winger is also worth less than DMan.
Comparing the players: Byram is better defensively, size, skating, faster, tougher, puck handling & leadership. Caufield has the better shot and reliant on the C and Dmen to provide the pass.
I don’t believe it’s close Byram is a significantly better prospect.