I have a 30" x 21" 22 ga. stainless steel backsplash with 4 (3/16") mounting holes 3/4" from edges. Since I will be using 4 screws to put it up, can I use removable (not permanent) double sided tape, e.g. DUCT brand, over much if not all of its surface to keep it from buckling or bowing out? The sheet is set back from a cooktop by about 5 inches.
I would assume that it'll get warm at times and use a product that won't goo apart as a result. Anything that's stiff will leave you with ripples visible from the side.
A panel adhesive that lists suitability for metal will give you a smooth finish and lasting bond. Use a small v-notch trowel to distribute it flatly and evenly to avoid rippling.
Alternatively, attach a sheet of felt to the back with double-sided tape to act as a vibration and noise dampener and just use the four screws.