I got them as a 4-stack: yellow kite at the front, followed by red, blue, and then yellow again. But as I wanted to be able to fly them with Flying Fish, my aim was to turn them into two 2-stacks, each with a yellow kite at the front. So this was a case of cutting the stacking lines between the red and blue kite, reversing the order of the blue and yellow kite, and adding a bridle to the (second) yellow kite. Plus whatever TLC was necessary (e.g. replace the cracked or broken t-pieces).
And then it was a case of waiting for a windy day, which, at this time of year, didn't take very long ...
First tried out both of the 2-stacks separately, which showed they handled pretty well!
And then the moment of truth .... would they fly well together, given that I tied the bridle for the yellow/blue stack myself?
Both stacks launched easily, and off they went!
No noticeable difference in speed and handling, and they flew together quite happily. One thing we had to be aware of more than usual: ground position. This was the first time we'd ever flown stacks together, and certainly the first time we'd flown stacks with tails as a pair. So we had to make sure the front kite of the leading stack didn't catch the tail of the back kite of the following stack. We had one tail catch, but got out of it again quickly.
Flying infinities, parallel loops and circles, getting in and out of wraps, and basically flying anything that doesn't involve sharp corners (which Peter Powell Stunters are not good at) really created a colourful spectacle thanks to the double tails.
Which brings me to the one disadvantage of flying multiple tails ....