Can installers inside mount thick insulating cellular shades over our uneven, decorative trim?
As the windows are right now an inside mount would have the shades hitting the top of the lower sash. 

I also like the look of a inside mount much better so I recommend a small modification of the window trim to accomplish this.



Remove the trim indicated by red arrow. This will leave a flat plane indicated by yellow. To this flat plane add a 3/4 board about 2.5-3” wide around the window.



Then it’s just a matter of measuring the width inside your new boards to get shades cut right.