Due to the resolution dependence of erosion I'd like to suggest a convenience node to help bypass this problem. Of course resolution independent erosion would be the preferred choice but maybe this is more viable. What I would love is to be able to have outputs set their resolution. However, this would potentially be very bad when you have such nodes that are dependent. The output resolutions would create inconsistent results.
So maybe if there was a new node. All it would do is bake its input (at a preferred resolution separate from the world res) into a bitmap and output that bitmap. Perhaps you don't let the user link anything pre-bake node hook into anything post-bake node to prevent inconsistency. Ideally, there would be a small amount of smoothing to make up for the lower resolution.
This idea is, I like my major terrain features at 512 but I want to further detail it at higher resolutions. If I set my res to 1024 all my large terrain features that result from erosion are replaced with smaller details.