How to fund software development, without the problems of proprietaryness or antifeatures, is the perpetual quandary of our time.
A possible method might be what I'd call "code shares". Here the author of some code might receive payment for support in the traditional manner, but because the authors resources are limited they might issue a number of shares, perhaps corresponding to lengths of time. Like other kinds of shares these would have a valuation, and customers could buy or sell shares amongst themselves. Each share is basically an entitlement to a certain amount of support for the given code base. Cryptographic methods could be used ensure that shares are unique.
A possible method might be what I'd call "code shares". Here the author of some code might receive payment for support in the traditional manner, but because the authors resources are limited they might issue a number of shares, perhaps corresponding to lengths of time. Like other kinds of shares these would have a valuation, and customers could buy or sell shares amongst themselves. Each share is basically an entitlement to a certain amount of support for the given code base. Cryptographic methods could be used ensure that shares are unique.