I think materials require design specific to the material.
Crankbait builders are very particular about what they build with, because they learn how to make a material behave in a manner they like.
In my experimenting, I've been able to get Sintra to behave exactly how I want it to, but I'm sure if I were to attempt the same design with balsa, I would have to make adjustments.
The obvious difference is density. Balsa has a specific gravity of .15-.20 while Sintra is .50.
What this immediately means is that Sintra is going to require a smaller ballast for the same rate of buoyancy.
Another thing - and this is just me thinking out loud, because I don't have experience with balsa - - is that a higher density body needs to be pushed farther before it destabilizes.
Here's one example of what I mean by that.....on a lipped bait like a deep diver, positioning the line-tie closer to the nose causes more instability and widens the action - to a certain point. After that point the crank doesn't work.
When I designed my Sintra deep diver, that point seemed to be closer to the nose than comparative wooden cranks. A lot of expert wood crank builders told me that they thought it was way too close. Perhaps it would have been with a much lower density body, but perhaps more force is required to swing the Sintra body - - allowing more "force" to be designed into the spec.
In the end result...my crank has more kick and liveliness than a DT-16, which is made from balsa...so design I think is a big component here.
Another example....lip size. I designed a small 2" shallow crank - and wanted something very kickin' and lively. I got what I wanted, but the lip is much larger than you would see on a comparative balsa crank. Once again - is it that the heavier Sintra body requires more force to destabilize, and can therefore have more force applied against it?
Another spec which it seems like I can push is the distance from line-tie to lip on shallow cranks - which makes for some of the biggest differences in crank behavior that I've seen.
Perhaps I'll pick up some balsa, and create exact designs of both to actually see if what I'm talking out of my arse about is actually the case. I'm very curious, and I've been wanting to mess with wood at some point, anyway. I'll always have a soft spot for it.
Here is that 2" crank....kicks like a champ.