This project successfully upgrades to version 4.25. Which is the engine I am currently using with the product.
Epic has done a great job in "upgrading all previous blueprints for backwards compatibility.
With that said, This pack comes with allot of features and is very detailed in terms of functionality and therefor potentially very complicated.
I would recommend it, but be warned there is a large learning curve and the systems are built without quick modding in mind. You basically have to understand how the creator built the system and then modify whatever is needed. This is very complicated. Not a simply component system for beginners. I would add plenty of the weapon creation requires skeletal meshes which is unfortunate because you need knowledge in DCC programs to create custom weapons. That said, I have not tried VRE. I assume its a cleaner process working with VRE and VRE is now more advanced features.
With that in mind. I do have some of the original tutorial explanations of features videos for anyone who already purchased this pack and needs them. I can upload them to my channel if someone in need of them just let me know.