Ive got a stone veneer outdoor grill station and some stainless steel cabinet inserts. I’d like to fill in the voids where the stainless steel meets the stone veneer. I was thinking I’d just fill it with mortar, but I’m not sure about mortaring next to the stainless steel due to expansion/contraction etc. Then I came across this acrylic Mortar repair from quikrete. It’s a sanded acrylic that comes in a tube for a caulking gun. Here is a link to the data sheet. [url]https://www.quikrete.com/pdfs/data_sheet-mortar%20repair%208620.pdf[/url] some of the voids to fill are up to an inch thick which I fear could be a problem. Ive attached a couple photos to show the area that I’m trying to fill. Appreciate any advice from those who know. Thank you!

JUst ordered the tile for the back splash in my kitchen. There are numerous outlets and plugs that I have bought box extenders for one of them being a 4-gang. My question is should I extend the boxes before tiling or after laying the tile?