My suggestion is simply to change:
public static final double BASE_DAMAGE = 8.0; (row 92)
and
public static final double BASE_HEALTH = 60.0; (row 93)
in the 'TameableDragon.class(.java)' to pull values from a config file instead of fixed values. This will be a huge QOL improvement for modpack developers.

Actually, I don't think this would be that straightforward because those values are used at build time to generate the mod's data, so they can't be pulled from configs at that point. Not to say it's impossible to do, but it would require more work I'm pretty sure.

The simplest way I suspect would be to pull the data the same way as a custom breed but override the built-in breeds. So far I haven't gotten that to work with code as-is, but that could just be a me problem.

I've actually had this topic at the back of my head for a while now.

It's definitely possible to do it regardless of the baked nature of the attribute system, as it can be done at breed initialization, but its the matter OF breeds that becomes an issue.

Those values you mention are base stats. It becomes a conflict of interest when a dragon breed has custom attributes themselves.

It's not (feasibly, intuitively) possible to have configs be able to configure dynamic based registry systems (aka the breeds) at the moment.

I could certainly implement configs to adjust the BASE stats if it's a desired option, but it'd be limited, if not confusing to configure for the end user.

I'm going to close this as not planned as I've made my decision going forward with this idea.
I don't feel it'd be a good idea to implement due to the complexity both for the end users and the way to implement it.

After all, this is already possible to do with datapacks now, and I feel it'd just be an unnecessary layer of complexity.