One trick to figure out...you have to lower yourself a bit to remove your platform. But then you can't stand up to unweight your tether for descent. You would need to already be on your descent rig before you take off your platform (unless you had aiders or something to stand on).
How do you guys address this?
Im climbing with my tether and just an aider.(until my 1 helium stick arrives in the mail.)
With climbing with a tether and aider I just climb down to my platform on the aider. I hook up my L belt and unrig the platform and stow it in the bag on my tree saddle belt. I unhook and stow my L belt and climb down with the girthed aider and tether.
For 10 years I used tree climbing gaffs and the L belt to climb. That was easy. Stomp the gaffs in the tree just below the platform. Hook up your L belt and untether. Climb down to the platform with the L belt and gaffs. Unhook and stow the platform and climb on down.
If I was rappelling out of the tree... Id get my weight on the rappel line then untether.
I'd rappel down to where I could work with my platform..and lock off my decender so I could work hands free off the decender allowing me to unhook and stow the platform with both hands.
If your using an ATC for rappelling you simply take a leg a wrap it around the rope hanging below you a bunch of times terminating with the rope below you running down the inside of your boot and off the instep. Then you place the the sole of the other boot flat footed against your other boot with the rope pressed into the boot of the leg your rope is wrapped around. Its safe. I have worked on rope many times this way and at great heights.
If your rappeling with a fig.8 decendar its even easier. All you do is make a upward hopping motion with your weight and bring the brake rope up, over and to the complete other side of the decender effectively hitching it off. Then you can work hands free to unhook and stow your platform.
Yeah I know folks will need a pic or vid of how to lock off an 8 decender....
I'll look it up and post something next.
Locking off - figure eight: http://youtu.be/YQoUejJaVaE
This shows a FULL lock. I have never had to use a full lick. A "half lock" has always held me fine. When you pull the brake hand up and over to the other side that is the half lock. Wether you need full lock or half lock depends on how much friction your getting in your system.
Experiment with your set up and see if half lock suffices or if you need full lock.
Hope this helped,
Umbra