your platform breaks or you fall free of the tree hopefully the seat portion of the climber can withstand the jar and hold you suspended by the harness. If the seat portion of the climber is what breaks initially, the platform should still be under you.
Not good. You need an independent connection to the tree; hence the body harness and safety rope. This is for redundancy, what you're proposing defeats that.
What is the hurry? It's not hard or really time consuming to climb a tree with a traditional climber; and simultaneously moving your safety rope up the tree (or down the tree) as you go.
Kindest Regards,
-Will in Maryland