Can I register tracks for Soundreef In-Store and, at the same time, on platforms like AudioJungle, Jamendo, Rehegoo etc?

No.

Management contracts are exclusive, so the same track cannot have several different managements (for example, Soundreef and AudioJungle), because conflicts would arise.

Therefore, before registering with one of these platforms, we recommend that you check with their Customer Services whether their conditions are compatible with Soundreef's In-Store service.