I am working at a very large software company, don't know whether that qualifies as enterprise code :). Yes, if you do customisations of open source software w

I am working at a very large software company, don't know whether that qualifies as enterprise code :). Yes, if you do customisations of open source software which could reveal trade secrets, I wouldn't expect this to be back-donated, and you could do that only with permissive licenses in the first place. But the large majority of open source software means just using it, and if it gets modified at all, it consists of bug fixes an small enhancements, that can and are back-donated to the projects. And as you wrote yourself, Sony tries to get the changes which don't disclose their trade secrets into upstream to reduce the merging load.