Why did he think that plywood was necessary? Full pics of your cabinets? Normally no plywood or any type of subtop is required. As far a hacking up the cabinets you would need to show us a better pic but typically no necessary if proper layout and measuring is done.

Ikea cabinets. So should the plywood have been cut before being nailed down?

Are the images sideways?

Is the plywood laying across the tops of cabinets and the quartz resting on that? THAT is common in the western US especially where slabs are more often 2 cm instead of 3.

I wouldn't worry about the extra cut in the cabinet. Sloppy, but you'll never see it when the cooktop is in. I suspect most people who are happy with their kitchens have a lot of uglies they don't know about.

Thanks Fori! Yes, images are sideways. Yes, plywood is laying across the top of cabinets, then quartz on top of plywood. Thank you, just wanted to make sure the cabinets aren't going to collapse on me a year down the road..

When I had my kitchen renovated a few years ago, I carefully researched licensed carpenters and interviewed a few. The one I chose happened to be one that my kitchen designer loved to use❣️Lucky for me❣️He did a beautiful job, no major issues. I suggest people research all the craftsman they plan to use, and get references, and look at photos of their work.

The cabinet is the least of your worries. Your engineered stone is completely out of warranty as there are no radii in your cutout corners apparently. Nasty tool marks are creating stress risers. When the heat from the cooktop cracks the top, the manufacturer is going to tell you to pound sand.

The cabinet isn't done being hacked I'll bet, since few cooktops are 3cm thick. The cabinet will be fine.