Just to help out with what I am on about here goes.
To get filagree look you want some broad structure visible and some fine whispy stuff showing. This is dependent upon the etalon setting. Usually that is located some where near center of the band pass. It will depend upon where you etalon comes on band in the red wing and where it goes off band in the blue wing.
With getting even illumination you need to look at the entire frame and watch for slight brightening in one side of the sensor. Move the scope backwards and forwards and up and down to confirm you have the illumination right. Then start your run once you have the illumination right. Moving the scope will show uneven illumination. Even Lunt scopes have some uneven illumination, it is minor but still there.
Blue end - I should have used blue wing. So to explain. The etalon covers from the red wing to blue wing of 656 nano meters. These wings are not separated by much, but enough to give different effects. When the image is at the blue wing the structures look bolder and eventually look rather odd. You get there by winding the etalon all the way in on a pressure tuner of a Lunt. With the red wing, just undo the etalon all the way out and that is the red wing. You just get spots and nothing else. This is how I understand it anyway.
See these images
Just keep collecting data and processing. It will come with time and persistence. I did lots of reading and contacting a few prominent solar imagers overseas for tips and clues on what to do and how to do it. Part of the fun though is discovery via research.