You may find some help from my Glowing Sun with Prominence share.
https://planetside.co.uk/forums/index.php/topic,24436.0.htmlI sort of gave up on the project as it takes awhile to preview just for adjustments on my machine. I have a v2 edit of it somewhere. I'll try to dig it out.
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Looking at your current approach, you may actually find interest in my Meta-Layer approach, and subsequently, what I just figured out, altitude variation for ML Clouds.
https://planetside.co.uk/forums/index.php/topic,25956.msg257782.html#msg257782The key to create a Cloud Meta Layer for this type of approach is a cloud layer with a large Depth centered in your area of effect. For example, a depth of 5000 and a altitude of 2500 will fill 5000 meters from altitude 0.
You can than use a Surface Layer with the child input being your Density Fractal, and pipe that DF into your Breakup a well to control breakup in fuzzy zones to conform to your cloud shapes.
Than you create a distribution shader and limit it to your desired altitude
in position in texture, which means the altitude values will not be accurate and take some playing around compared to Final Position (like what cloud layers themself seem to use). We need position in texture to be able to warp the Altitude/Y axis or anything else.
You can than do a Warp Input Shader on the distribution shader, and feed it a Redirect Shader with a PF assigned to the Y Input, here you can use displacement to vary the whole Cloud Meta-Layer on the Y axis.
Since you want to create solar flars, you'll want to mask the Distribution Shader with a elongated Simple Shape Shader, or maybe Perlin Ridges or Voronoi Ridges with colour offset.
.... I'll try and make an example.