A properly cut SS metal band, fabricated so there are no sharp edges, properly to hide it - and I think that might break up the length nicely because from the photo is looks overtly massive although I can't be sure from that photo - do you have a photo you can take from a distance?

If it's not actually massive in conjunction with the rest of your kitchen, I advise you have it re-done, and fabricated by someone who knows better than to use tin snips, as chispa stated. That's not acceptable.

Here is a pic from further away. Chipsa and 2ManyDiversions, to have this redone, would I remove the hood and take it to a metal shop?

Ok, after seeing the pic, no I don't think it's overwhelming now. Carol, I can't speak of this with experience/authority, but were it me I'd call custom cabinet makers in your area and ask if they know anyone who can do this type of work. At which point I'd get references, then you'll find out if the whole unit would need to go to the workshop. I'd just assume yes, but perhaps they can fabricate something and bring it in. Rather than a 2-piece, it would look far better as a single unit.

I think aesthetically any kind of add-on band might look wonky. Similarly, I think even getting a shop to recut the bottom or bend over the edges would look strange. I'd get something made to cover the entire thing so that it looks like one bit. Make sure that it attaches solidly so that it doesn't rattle.

omg. That is awful. What was he thinking????? I'm having a hard time understanding why he had to do it and why such a botch job. You are very mellow to accept that.

I think he was: A) uninformed about the fact you can't add on to that vent without it looking bad B) using snips is just stupid. As to why, the vent was too short, so something had to be fabricated. Just not that. someone (not sure who the OP can find) needs to redo it all. Tabs and screw holes are not a big deal to add.

The curved glass canopy is what makes this all a little more complicated. If you fabricate a new cover, it has to trace the same shape. That's of course entirely doable. A laser cutter or a water jet would easily be able to cut this shape. But you need to pay somebody to program the shape; and they might need access to the hood to take really precise measurements. Also, you need to pay for the length of the cut. That's how billing for these things usually works out.

The good news is that the cover doesn't look structural at all. You can make it from relatively thin material. That drives down the material cost, and it substantially drives down the manufacturing cost. Cutting thin materials is a lot easier than cutting thick ones.

My guess is that you'd still be looking at several hundred dollars to make a custom cover including the bottom cut, some tabs for the screws, and the openings for the exhaust. In the big scheme of things of a full kitchen remodel, that's just the expected cost of overages. But compared to the cost of the hood, that's a painful extra charge.

When all is said and done, it'll look great though.

Is it possible to put the cut piece inside of the uncut?

If a lot of additional cost appears to be needed, it might be a better solution (certainly a better performance solution) to acquire a more conventional hood with capture volume and without a barrier between the first plume bounce and the air intake.

Thank you all for your comments. I am in touch with a local fabricator and asked if they could recut the lower duct cover. There is plenty of height to work with so if they can smoothly cut something with corners I can reuse what I have. Or, have them make one new piece, but coordinating with the stainless color on the canopy unit will be necessary.