Only because we haven't seen them, doesn't mean they weren't done yet. Till the recent pics with external payloads came out, we only had seen pics with external pylons, which doesn't mean they wouldn't had made weapon trials earlier. Internal carriage and weapon trials obviously are not that visible and would require official pics to be released.
Wrt the weapon pack, I would be more interested in what weapon pack IAF aims for FGFA. It is crucial for us to have an own operational requirement and chose weapons that not only fit to the weapon bays, but also fits to those requirements. So we should only choose those Russain weapons that are good for us and not just everything that is available, just like we shouldn't take any Indian weapon, only because it's Indian.
