There's no hood depth, and certainly no internal (cavity) measurements. I will only guess that extractor insert width is ~34" for a 36" nominal width unit

Your cabinet installer needs to be consulted if you expect him to install it into something that wasn’t custom designed to receive it. This is where using the cabinet company’s hand in glove designed for each other models saves you time and expense. By the time you pay an installer to kludge the two together, you could have bought the more expensive models from the cabinet company.

And the whole installation needs to be 30” from the cooking surface, minimum.

Who is installing the hood?

I am currently going through coordinating my hood with my HVAC people who are doing the necessary duct work and the cabinet maker who will make the hood cabinet to fit whatever insert I get. At least to me the measurements seem more of less the same for my 30" inset which are all about 28" give or take a 1/2".

My current issue is that I didn't realize I needed a rear vent versus a top vent since the soffit above that wall is a structural concrete beam so they have to install the duct work to the vent behind the sheet rock.

Stanisci offers blowers sized to fit if you are getting a standard size. Safest way if not working with a designer, just check with installer about ducting.

Thank you for your input! I hadn't even thought about the ventilator portion until after I designed the kitchen. I was naive in thinking that I'd be able to find a cookie cutter ventilator to put in my decorative wood hood! Now I'll just have to suck it up and pay the extra money so that I know what I'm getting fits in perfectly. Now the question is... 600 cfms or 1,200?? We don't really fry anything, and it's going over a 30" range, but it's an open concept space- about 13x30. It's funny how the things you don't even consider when planning a kitchen end up being the hardest to figure out in the end!

Either blower size will require the addition of a Make Up Air system to the home. What would be your plan for that?

Contact the company making the hood for the insert measurements.

For CFM, I think that you should get your HVAC company to assist you with analysis, materials, and cost. If you live in a cold climate, heated make up air will need to be considered.