I don't know about your windows, but my windows have a piece of trim (stop) all around sides, top and bottom, b/t the jambs (inside "frame") and the actual window frame (the window unit without the sashes). I just installed the headrail right up against it at the inside top of the window and it/they were skinny enough to stay entirely within the (extended) jamb but with the shades mounted to the front side of the headrail they hang in front of the bottom sash. If you don't have extended jambs you may find the shade hitting the bottom sash - so I'd say measure the clearance you have to the front of the sash (starting from any stop you may have installed at the top jamb/header) and make your headrail that deep, with shades hung in front not under and then you should clear the sash but still be within the window jambs. If your sash is pretty much flush with your drywall then you're going to have the shade hanging more in front of the window but as long as you don't make the headrail too deep or mount it too far forward you should at least be able to get it back farther than the window casing if you don't like the look of it sticking out. Worst case, if you don't have deep jambs and still want inside-mount shades, you can mount them so they clear the bottom sash and hide the headrail sticking out with a valance going over and outside of the window casing (outside trim). Don't know if that's a look you want or if you have room for rod outside the casing. I hope you understand my explanations of window parts, I don't know how to label pics! If you look in this pic, you can see the white vinyl window frame, then the stained beveled stops on the sides (barely) facing you, the jambs are turned 90* to the camera, and the casings are applied overlapping the walls and showing a small bit (reveal) of the jamb all around the top and sides. The bottom piece of wood that sticks out from the wall is technically called a stool, the sill is the bottom horizontal part of the window itself that is behind the bottom sash to the outside when the window is closed and is the depth of the exterior wall. FYI, the trim that I am missing under all my windows (under stool) is called the apron. Some people don't have stools or aprons on their windows, they just have casings applied "picture-frame" style all around the window. HTH

I'd do inside mount. If I could, I would make the center window into 3 separate but abutting shades. I would have them capable of dropping to the floor, even if that meant that when you lowered the shades, you had to pull them out a bit to clear the lower window frame. Of course this doesn't mean you have to lower them that far, but you should have the capability. The wider the shades are, the more expensive and the heavier to lift, plus it puts more strains on the strings and makes them more likely to break. So going narrower has its benefits.

Thank you for the response. For reference, here is the hood we have: https://www.whirlpool.com/kitchen/cooking/hoods/canopy/p.WVW53UC0FS.html It will be vented outside through the roof. is the back of the vent stack covered with steel too? I was told the back is open due to it being on a wall. Are all 4 aidss covered in steel? If so, then I guess it wouldn't be so much of an issue.

They of course WILL make them. and what they will not tell you is it is GONNA be a pain in the rear end. Over time, simply the lift and strain on rings and cords, and the heat that builds up with every yank, will "burn out" the cords. Then.......no matter how well crafted? Plan for puff and fluff ritual with every yank back to raised position. You can spend the money and find out. I wouldn't let a client do it at that width. Do as you will. Come back with the regrets: ) The treatment is INAPPROPRIATE for your windows. But yes....... someone will be happy to take your money. The corner will be the least of the issues. Hide an inside mount privacy treatment under a "fixed and never moving " roman shade valance. Or do not do it at all. Ya heard it here.