I understand the concerns, but I think it's generally hard to predict whether open sourcing something will result in an unproductive division of resources (man power of volunteers), or whether it will ultimately be beneficial, e.g. by promoting positive competition, by making it possible to merge functionalities, or by simply having two good libs being developed independently... (like there are many good text editors or scripting languages out there, with each having their fan base).

So I'm not really sure what to advise, in particular as I don't even yet know the library in any reasonable detail...