Thank you for the reply. The delay is okay; I am now also travelling/abroad and there's indeed much to do.
I understand the dilemma coming from potentially slow adoption under a copyleft license. But since you aim for both freedom and quick adoption, I believe the best existing middle ground to be weak copyleft.
The major difference of weak copyleft to permissive licensing is, according to my knowledge and opinion, the protection of the core program's own freedom. This would mean that people can freely use and bundle the program with non-free software.
In that case, those who wish to make and distribute proprietary software could still make use of PeARS, developing their own software to make use of it without directly contributing code.
On the other hand, with a permissive license, people could do the same thing, except that they could modify the original code and distribute it as non-free. I do not know if that possibility is attractive enough to provide faster adaption of PeARS, but I believe it would raise some important risks and issues for the whole ecosystem, which could then become something too distant from the ideal.
Again, I am not a programmer and do not understand the internals of PeARS well, so my fears and/or assumptions may be wrong. But whatever the case, I'd like to envision a world where our technologies are well distributed and provide us with freedom, privacy and security. Should there be a choice that could likely not bring us closer to that world, but instead bring us nothing or farther away from it, I believe it should not be made.
In any case, I'm glad there's interest in this, and whatever may the final outcome be, I hope that it will help PeARS be the step to the above mentioned future!