With all these modifications, he will probably push best L/D from 44 to 44.5, plus he will be a test pilot for the reasons you cite.

And after the first contest he will have learned that it's not max L/D which matters, but L/D's at 90 ot 130 kts. At these speeds, a Kestrel basically falls out of the sky, regardless of any lipstick. Especially if the span has been increased.

My advice would be to sell this ship, and get one he'll fit in without making changes. ASW20 would be a good start, or Open Cirrus. Both are less, or significantly less, than 30k.