Rear Drive Shaft Option

Last weekend, while googling to find pinion angles, I came across a photo of a rear drive shaft set up that I have never seen mentioned or used on .

Some guy used a front shaft on the rear. I presume he removed the double cardon joint and attached the yoke part to the front of the drive shaft, and attached it to the transmission, then the other end (the greasable end) he just put into the rear differential.

Now, my question, since the front drive shaft is telescoping does this play any type of advantage into using it on the rear. My thought would be that you could have some slip in the yoke and also in the shaft and allow it to be a little more "flexible."

Is this a good idea, a stupid one, and is there any benefit?

A front shaft is used in the rear when a slip yoke eliminator is installed. This is a fixed flange or yoke that attaches to the output shaft of the transfer case and does not silde. The front driveshaft is used, usually temporarilly but not always, because it has a slip joint to allow extension and retraction of the drive shaft. It would not work to have a slip yoke and also a shaft with a slip joint.

I am using a front drive shaft on the rear on my jeep. But I also have a slip yoke eliminator.