I tested this setup for a while now and I'm super happy with it.
The webbing has a good bounce and is super soft (both for the feet and when you grep it with the hands).
One little downside is, that it starts getting a bit round, after 5-10 freestyle sessions, where you grep and pinch the line often with your hands. But this resets when you give it some hours of rest and rig it again.
The whole setup is durable, strong and suitable for a lot of trainings sessions.
17% longer backup seems perfect to me, it has a tiny bit bigger loops than ideal, but also room for the main to stretch a bit over the years. I would recommend rather a bit longer backup than too short, like that you could still tape an small "S" at the end of the line, to shorten the loops.
The trickzone needs a tiny bit to get used to (if you never tried one before), but is so essential in my opinion now. If I freestyle on a line without it feels weird.
You should tape it on the sides to the mainline, so it's not moving anymore (try to stretch it out), but be careful of not making the tapes too tight, otherwise this will bend the mainline.
Overall in comparison with the other freestyle setups I've tested, this is more durable and more soft but a bit heavier. The bounce feels (depending on the tension) quite explosive, and is in my opinion better on 60m+ lines.