I would think it would be ok.

Are there going to be upper cabinets flanking the hood so they can help capture the FOGSS?

If yes, you might be ok...

Do you stir fry or do other high heat cooking? If so, you might not be ok.

What and how you cook is just as important as your fuel.

yes, there will be upper cabinets on either side. I stir fry occasionally but nothing terribly smokey

The 36” width will be fine. I am more concerned with the 21” depth. Will it cover cooking you do toward the front of the cooktop? I also want to know what a “hybrid baffle filter” is? I couldn’t find an explanation on the Zephyr website, which concerns me, but maybe I missed it. Lastly, the Zephyr Siena hood requires an 8” duct to the outside. Is that what you have?

I do same size cooktops and hoods very often but it also IMO requires a choice to up the CFM to get good capture. How the hood looks is secondary to function.

We have exactly what you are considering, except ours is the Zephyr Breeze II. It has plenty of CFM to carry away anything we have thrown at it. Ours is vented direct through the back in a rectangular duct so I don't remember the required round size. I can post a pic if you like.

I had that exact set up in my old kitchen, except my hood was 18" deep, and it worked just fine. I didn't do any high-heat cooking though.

Expansion angles at selected heights of an induction cooking plume were slightly smaller than for a gas cooking plume per Thermal plumes of kitchen appliances: part 2 cooking mode, Kosonen Risto, Koskela Hannu, Saarinen Pekka, Energy and Buildings. The difference in my view was not enough to argue for a significantly relaxed hood capture angle relative to the pan when induction cooking. In other words, if the hood is not supplemented by side cabinets or preferably side skirts/curtains (as on commercial hoods), larger pans will generate plumes that can exceed the capture angle of a hood having the same width as the overall range.

I have a 36" hood over my 36" induction cooktop with upper cabinets on either side. My hood does cover front to back of my cooktop too. I don't remember the CFM on mine. I believe it's 600 but either way I've never used it higher than level 1. Haven't needed to.

I'm doing "new kitchen" research for a kitchen we likely won't build for another 3-4 years. I currently like the Bosch 800 36" induction cooktop and I'm considering the Bosch 36" pullout vent. It snugs up against the bottom of upper cupboard and when it's pulled out, the vent turns on as well as 2 lights. I like the look of some vent hood covers, but I don't like the thought of me or my spouse bumping our heads on it. The pullout vent seemed like a nice way to keep things simple.

I have a 36” hood over a 36” induction cooktop. It works and looks great.