The major problem with Wilbur's flow calculation is that it's calculated as either 8-way or 4-way connectivity to the nearest sample. Either of those connectivity options will pretty quickly lead to up/down, left/right, and diagonal artifacts. The purpose of adding noise is to confuse the flow finder to minimize the visibility of the artifacts.

The river map finding feature referenced in the pseudo-Alps description in the Muna thread is pretty much the first step of Incise Flow (finding flow) with processing to go to the texture channel rather than the altitude channel. It has the same problems with short channels that Incise Flow does. Note that you can make a block of mountains with rivers generally where you want them by drawing your own mask with the main river trunks already present (it's pretty much the same as the regular operations).

One interesting tool that you may not have played with is the Max Length option on the Precipiton Erosion feature. Changing it to a positive value greater than 1 (for example, 2) will move altitude downhill by a limited amount (I think it's n-1 steps). This operation results in what is pretty much heat diffusion (it's a randomized heat diffusion that gets little spikes due to missed items). It's a rough approximation of thermal erosion, just as the precipiton erosion is an approximation of fluvial erosion.

You can make a few mountains and use those as brushes for stamping rough shapes, if that idea helps any. Being able to pick brushes randomly from images in a directory is an idea on the wish list.