Reducing bulk with nerves of steel

This is going to be a long post.
One big challenge we have when we make pleated top treatments is eliminating excessive bulk on the board where the pleats create layers of stacked fabric.
The usual techniques were not going to be sufficient for this collaborative project: kick-pleated valances out of an upholstery fabric with a not exactly lightweight sateen lining.  What I was asked to do required nerves of steel, or a personality comfortable with taking risks, or a supreme self-confidence.  I'm not sure which applies to me.

We started by laying out the lining so the selvedge came 3/4" below the eventual board line.

The valance was assembled: welt was applied to the bottom, the face and lining sewn and turned and pressed.  Then  the lining was secured at the top with a tag gun, and blind-stitched it to the face, using a thread color that would disappear against the face fabric.  This only worked because the face is an upholstery fabric and was so bulky that the blindstitch didn't show.

At the top, a line of staystiching exactly at the board line helped us feel more secure about the cutting we were about to do.   (I'm showing this pic but I know you really can't even see the stitching line).

We had already carefully plotted out the pleat spaces, and now we cut down into them all the way TO THE BOARD LINE, and believe me, that was scary!  We angled the approach so if we were off by a tiny bit we'd have some wiggle room.  I've never done anything this way before.  I knew we had to be 100% certain that we had not made a mistake in planning the pleat spaces.

As if my nerves weren't already frayed, we then overlocked the angle and the pleat space, and cut the return end down to 1/2" and serged it, because it needed to go around a curved board end.  Here's how it looks from the back.  The top of the cutout space is the board line; the lining comes to 3/4" below the board.

Time to staple.  The dot marking the center of the pleat space is centered at the pleat line, the fabric aligned to the top of the board, and 3 staples were put in to secure it.

Since the fabric was cut so the pattern would flow across the pleat matching up, we first secured the outer portion at the return and at the pleat line with a pin to make sure it was all laying out correctly.

Once we knew the pattern was matching up, we stapled the inner side of the pleat; it was a little tricky holding it all in place and wiggling the stapler in there.

Then we finished the outer side of the pleat- voila!  The only fabric on top of the board is the main body of the valance.  All of the pleat ends at the board line, and that's upholstery fabric only, because the lining doesn't come up that high.

The curved end had already been reduced to just 1/2" on the board, and now just needed clipping.

The fabric just laid down, the clips overlapping,  and curved with nary a bubble or pucker at the board line.

Here's how it looks from the wrong side.  It worked!

This was long!  I'll finish up tomorrow with the top welt cord.