Yes, I believe that's possible. But a careless tweak can easily "ruin" other ski performance attributes. Surely you already know there are complicated trade-offs between many variables in ski performance---not just between rebound energy and edge hold.
If you merely seek fulfillment in the design "journey", then by all means go for it and have fun---but $2k for custom construction seems excessively expensive to me if the "destination" sucks (i.e. if you end up hating the performance of the actual ski).
On the other hand, if you want to actually hit the performance objectives, then I'm sure we all would have plenty of advice on that. You know, like lean on Wagner's experience in interviewing people in your situation---maybe they've already solved your problems after serving other similar customers in the past. Also, by trying more ski models, you might better dial-in your own tastes in ski performance, and maybe get even better at connecting ski model attributes with your tastes, etc. Who knows? For example, maybe trying an old Nordica Helldorado might reveal more about some of these attributes you like, and maybe an old Blizzard "The Answer" might reveal more about attributes you hate, even though those models are wider than your target...or whatever. Or if your performance objectives are truly absent in the market, then instead of rushing to spend $2k at Wagner, I'd say buy a cheap beat-up used Kastle MX/Stockli AX/Monster 98/etc., or maybe even just a cheap old race ski, and home-bend some rocker into the tail, and then go ski it to learn more. If it feels too beat-up and soft, then you can even epoxy woven fiberglass right onto the topsheet to stiffen it up, and go ski it again. No matter how unique you are, I'm guessing Wagner could nail it after interviewing you about your experiences with not-so-expensive ski experiments like that.
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