Wolf makes a 27-inch deep wall hood. See their Design Guide. ModernAire will likely be able to build whatever you want. Don't expect your ventilation solution (hood system and MUA system) to be significantly lower in cost than your range.

Thanks Kaseki. How critical is the 27 inches depth for the hood (vs standard 24) for my set up? (Bluestar Platinum 30, assume at least 900 cfm hood if not more, installed at the right height, but with cabinets keeping the hood's width to 30. I'd be grateful for any thoughts here. Thank you.

Out in the open, the effluent plume from a pan (aided by gas combustion products around the pan, where applicable) rises and expands. Most of the plume (for hot plumes) lies within a 10-degree from vertical cone extending upward from the pan edges. As the hood/cooktop configuration becomes enclosed by a back wall, and partially by cabinets or side skirts (primarily commercial), the hood effective aperture is partially extended downward and forward. This brings some of the entry air due to the hood system blower to be somewhat brought down and forward.

With sufficient enclosure all of the hood air will be pulled from the cook's position. But also to be considered is that air velocity away from a hood entrance falls rapidly. So when a hood just overlaps a front burner pan, even with partial cabinet enclosure, plume capture is chancy. If unsuccessful, there will be some uncaptured plume. This is not the same as hood spillage, where capture is initially successful, but plume momentum causes some plume reflection out of the hood due to insufficient CFM for containment.

So if forced for some reason to use a hood that isn't ideal in front burner overhang, one has to compensate by cooking the greasiest stuff on the back burners.

Of possible value would be generating a side view of the configuration with burner locations marked and various pan sizes marked, with 10-degree off-vertical lines intersecting or not the hood aperture. This may inform you of what pans to use and what you can cook in them. Ultimately, though, experience with the hood will provide a refined understanding of capture performance, because gedanken experiments with nominal plume characteristics will not address every fluid dynamical effect that occurs in practice.

That was an excellent explanation! Thank you Kaseki!

If you've a 30" range you should have a 36" wide hood and as deep as you can get (30" deep is better than 27" deep is better than 24" deep, etc.).

More: https://www.gardenweb.com/discussions/5161173/hood-faq

I thought it might be of interest to determine the front-to-back distance that is equivalent to the 3 inches beyond the cooktop plume expansion approximation on each side. That is, given the offset distance between a hob or burner center to a point 3 inches beyond the cooktop side edge, what distance to a likely wall position would there be if that same burner center distance was applied to a front burner on the front side.

On my Frigidaire Gallery induction cooktop, measuring to the step in the peninsula it is mounted on, the answer is 23 to 25 inches depending on whether one uses the smallest front hob (25) or the largest, highest power, more centered hob (23). These values can vary with the exact distance of the cooktop to the wall, and the amount of plume drift bias one will get at the front due to wall hood operation, which may or may not make up for the light bar's width where capture is dependent on hood flow boundary conditions.

In other words, considered in reverse, if one needs or desires a 30-inch deep front-to-back hood, one should also extend the sides further from the cooktop for equal plume capture effectiveness. A commercial hood at seven feet from the floor not using side skirts would need an overlap from a pan edge of 8.5 inches to meet a 10-degree plume expansion angle. Hence, for pans extending to a cooktop edge one would want a hood that was 17 inches wider than the cooktop, rather than 6 inches wider.

Overriding all of this is an aphorism that occasionally comes to mind here on the home-front: The hood don't work if it ain't on.