BASE
The Base tier is made to potentially cater for developer needs with fundamental components, or content covered. The Base tier can cover small tests/prototypes.
All the way up to small games or games requiring smaller quantities of the package, perhaps in just a small biome, or a minor part of it’s mechanics. For example it can make sense get smaller packages for smaller prototype, games or for those that require a little bit.
Do note, this may just be a helpful way to utilize the categories. And they are, and may be used in any way or outlook in regards to scalability/expansion.
BASE+
The Base+ tier is made to potentially cater for more developer needs with more components, or content covered. The Base+ tier can cover average tests, and bigger game sizes without much/any extra work on it.
Supporting more projects requiring bigger scales of the content or systems, perhaps in several biomes, or a bigger part of it’s mechanics. For example, it may make sense to get midrange packages for average scale projects, or for those that require a decent bit.
Do note, this is just a helpful way to utilize the categories. And they are, and may be used in any way or outlook, in regards to scalability. In any case, all packages are made for commercial use.
CORNERSTONE
The Cornerstone tier is made to cater for all developer needs, with more components, and content covered. The Cornerstone tier can cover bigger tests, and full project sizes without any work on it at all.
It supports more projects, which may focus on bigger scales and standards of the content or systems, perhaps which center on it for biomes or game mechanics.

For example, it may make sense to get bigger packages for bigger prototypes, games or for those that require a lot of that package.
Do note, this may just be a helpful way to utilize the categories. And they are, and may be used in any way or outlook in regards to scalability, or otherwise.