qgis - Dividing a buffer into segments based on path and distance

I have a buffer layer which I generated from a polyline layer and then dissolved. I then rasterized the dissolved buffer layer, thinned it based on this link and generated a new (more approximate) polyline layer which occurs at more or less the centerline of the dissolved buffer layer.

I also have a background raster containing values which I am interested in averaging later on. In summary my session looks something like this:

I would like to now find a way to segment that buffer layer based on a particular distance. This is the reason I thought that having a centerline polyline layer would be beneficial. In MS paint I have drawn an example of what I am aiming for:

I'd like to make the segments as perpendicular as possible to the edges of the buffer zone. I realize there is also the problem of how the segments are calculated when the road branches off as shown below. To this I would apply the algorithm employed by v.split.length, if possible.

How do I segment the buffer layer based on a regular centerline length of the dissolved polyline layer?