Why would someone privating their inventory restrict your creativity? Some people may have assets that shouldn’t be publicly viewable. If this is a serious roadblock in your development process, you need to learn how to make assets yourself instead of relying on free models.
I don’t know how much RAM Roblox servers have, however, they give you 6.4GB of RAM at the minimum (allocation scales based on your player count) for your game server, which means they must have a lot. Also, I doubt Roblox servers have a single core processing unit, considering you can use parallel Luau on them.