Maybe cut a piece from under the bench so that you have a match, then you could replace that piece with reflectix under the bench where you don't see it. I just had a similar need when I took the miniblind brackets out of my current
Boler and someone had cut the ensolite out behind them, luckily I had just replaced the over the stove window with one an inch and a half taller so I could salvage that strip to patch the holes