Know the mod is pretty new; are there plans to add integration for mods that add other ores? or is there available documentation/method for doing so in config?

Yes, that is the plan. My idea at the moment is to have several modded ore chunks included in Ex Deorum by default, just not visible unless some other mod that adds the full ore block is present.

I have yet to decide how I want to handle Ore Chunk -> Ore recipes when two mods add the same ore, since Config files aren't available when recipes are getting registered.

Here's the full list of ores I plan to include by default, let me know if I'm missing any.

Aluminum Ore
Cobalt Ore
Silver Ore
Lead Ore
Platinum Ore
Nickel Ore
Uranium Ore
Osmium Ore
Tin Ore
Zinc Ore
Iridium Ore

In the meantime, if you'd like to add them yourself, you could probably use KubeJS to add the ore chunk items and use a datapack to add the Sieve recipes. Here's an example of what a sieve recipe looks like.

"result_amount" is a Number Provider. The usable types for sieve recipes are constant, uniform, and binomial.

I added modded ores in Ex Deorum 1.3. Let me know how it's working for you. If there are any issues, please let me know.