Go DosDawg! Yes, constraint is in order indeed. Selling a D7 mod before a stable D7 release is in fact not only strange, but it encourages customers to go against company recommendations, and also works against the very point of having D7 betas.

Why so? Because beta-testers who stick custom modifications into their systems are generally more trouble than they are of worth in a product's development cycle.

"Don't tweak it if it ain't fixed yet!"