That’s true and fair.

… I feel like you can do this with the Mastodon admin already. Preferences > Administration > Custom Emojis. Enter in the domain whose emojis you want to see / get, search. Click the “select all” checkbox at the top, copy. If there are multiple pages, go to the additional pages.

Here is an explainer on architecture. It might be helpful. https://blueskyweb.xyz/blog/5-5-2023-federation-architecture