Reheat coil control valve location

[ChasBean1]

Application - standard CAV/VAV supply air terminal box with hot water reheat:

I usually see the reheat coil's hot water control valve at the outlet (hot water return pipe) of the coil.

Occasionally I see a "rebel" design that has the hot water control valve on the supply line.

I've seen a similar post in the past, but coudn't locate it. Is there a reason for having the control valve on the return line, other than convention?

Thanks in advance for any feedback. -CB