Oh, what a trial you have. Your colors and fabrics are lovely, hope you can get some workable advice. I use plastic templates from Brandy's and they are quite thin and I can iron over them -- and they are reusable. I usually spray starch the hexie, press, dry and then remove the thin template and press again.
Great advice to try, but it looks like you're going to have fluffy flowers, too many little gathers/pleats. When quilted it will still be wonderful.