How difficult is it to upgrade the Skydel GNSS Simulator feature?
Skydel/GSG-8 is essentially software-based since it is a simulator that runs on GPUs and SDRs.
So anything you want to add or update in Skydel/GSG-8 will always be software based unless you want to add more radio outputs to your GSG-8. In this case, it would be necessary to update your GSG-8 hardware.
Please check this post for information related to this issue:
How do I update software? - Skydel Discussion - Orolia GNSS & Skydel Simulation Community