Jamied,
I've attached pictures of my AXS on the small and big cogs.
Here is my method for replacing the chain on a new drivetrain where the old chain length is not applicable due to change of cassette or chain ring size. There are a lot of methods out there for chain counting, measuring, etc., this method is simple and has always worked perfectly for me:
1. Shift your derailleur down to the smallest cassette cog.
2. Wrap the new chain around the front chain ring clockwise and pull the chain around until it's about half way to the derailleur. Note, you want the loose chain end hanging beneath the chain stay and not above the chain stay.
3. Take the other loose end of the chain and feed it over the smallest cassette cog. Thread the chain through the derailleur arm and around the derailleur wheels. Pull the chain through the derailleur wheel until the loose end meets the other loose end of the chain beneath the chain stay.
4. Firmly hold the chain ring side of the chain in one hand. Firmly hold the derailleur side of the chain ring in the other hand.
5. Begin pulling the two chain ends together. As you pull the two ends of the chain together, watch the derailleur arm as it begins to tension and move forward. Keep pulling the chain ends until the derailleur arm is in the horizontal position.
6. While maintaining the chain tension, note where the two chain ends meet. Keep in mind you will be adding a quick link to join the two chain ends together, so accommodate for the quick link length. With your thumb, mark the spot on the chain where you need to remove the unnecessary links. Join the chain ends together with the quick link.
7. Here's the trick...With the chain on the smallest derailleur cog and the derailleur arm tensioned horizontal, you will always have the correct chain length when shifted onto the largest derailleur cog. Simple, and it works.
Note: If you have a double or triple chain ring on the front of your bike, you want to start with the chain on the largest front chain ring.