Are there any benefits to using a dedicated tag provider for each project? Is using different tag providers in the Gateway only for organizational purposes? Are there any drawbacks if I place 300K+ tags in the same tag provider in the folder structure?
It is mainly organizational, to make it possible for projects to have different default hierarchies. (Each project has a default tag provider property.) Do note that UDTs are not sharable across providers. You would have to place the definitions in all providers that need them.