I see what they did, and it's what I was thinking about too.
The cab heater return line is normally placed (at least on my tractor) where the heater is located on yours. By placing the heater where the return is normally placed they were able to l mount it on an angle. Clearly your tractor had enough slack in the heater hose to move it a couple inches down, hopefully mine has enough slack too.
I checked my tractor last night and it should be possible to get enough slack to relocate the return port a couple inches further away.
My next question is has anyone ever drained the cooling system on a cab tractor? I'm concerned that if I drain the system will the heat exchanger in the cab also drain and will I have to deal with an air lock.
I suspect there must be a check valve in the system somewhere otherwise wouldn't the coolant flow out of the rad when you take the cap off?
I was thinking I would pinch both of the heater hoses before draining just to be sure.