Fine grain resource rate control (mod?)

Is there a way to have fine grain control over the resource rate? I'm hosting a server for my friend group and want metals to have a 2x drop rate but all other items still have the base 1x drop rate (we had an awful time gathering enough iron to progress for the 5 of us last time).

If the solution is a mod, is there a way I can install that mod and configure it without forcing all my friends to also install the mod?