Is it necessary; No. Can you dress up your furs a bit; yes. WIll it add any to the value; maybe.
It is my contention that you should put your fur up to the specifications of your buyer(s) if you wish to maximize your return. I 'll give you an example; we had a buyer of hi end cats come to our sale and tell al that they would realize more for their cats if they "tubed" the front legs such that the buyer could see there was enough leg to make a specific critical cut after dressing. All those that heard this went to tubing legs. Some stuck straight up some resembled giraffes on a cross. Most did not pay nearly as much attention to the overall shape; some were very long and narrow some almost square. At the subsequent sale many pulled their cats because of low prices. The high end guy wasn't buying only the very very best and then was getting beat some. The pulled cats ended up at a local buyer who paid considerably more. This buyer cut off all the tubed legs...he couldn't bundle them for shipping!
I tube my legs just a bit longer than the elbow. I find that if I insert a 1.5 inch wide "lath", maybe 18" inches long, into the legs that I can get a nice presentation of belly. The "laths are inserted to extend almost to the upper part of the neck. The laths from opposite legs cross and form an "X" inside the pelt. When you insert the lath you can rotate it to show the inside of the legs spots which compliments the belly. While drying they hang laying close to the sides of the cat. I lube the laths with a little vaseline or neutral oil so they do not stick and remove them after a day or so. The legs will hold their shape well from this point on.
