I'm sure there are others with allot more knowledge on this than I, however I will tell you what I know, or at least what I think I know.
The prodigy has not been bred to any other form of T pos that I know of.
It has been bred with a sharp albino, which some has said is a "form" of T pos, this I cant say I agree with, however it is possible, nay I say plausible.
When bred to the sharp albino, the prodigy, that is, it did produce a visual morph coined "paradise" boa.
This does not mean that when bred to a BWC type t pos that there will also be a visual nor does it mean that the prodigy is the same as a BWC. What is does mean, in my opinion, is that it is possible that when bred to a BWC a visual could be produced, but only time will tell.
There is a distinct difference between BWC and prodigy, at birth and as they age.
Now the VPI t pos has also been bred to a sharp albino, only to produce double hets for both, which we should soon see what that will produce. I don't know of any VPI to BWC breeding or VPI to prodigy.
As far as the other lines, I personally don't have much info on them.
I personally feel the prodigy line offers a better base boa in which to make combos and improve upon its looks as well.
I have become a fan of the VPI tpos as well, with some of the pink panther stuff out there and some of the combos it really has come up the ranks since I first seen it appear on the scene.
What I think would be neat and needs to be done, is infuse the pink panther gene, characteristic into the prodigy line.
A pink panther prodigy (PPP) will be stunning.
Then throw in the jungle, motley, hypo gene in there and it is just as exciting as the stuff being done with the VPI line.
As I once heard someone say, "it's all good!"
Hope it helped a little bit, I may have muddied the waters a bit more then clearing things up..LOL.
Mike