A microwave over the cooktop isn’t going to be as good at venting. Why not do a slide in range (cooktop + oven) with a proper hood over top and then a second wall oven stacked with a microwave

Yes, you can put a microwave over a cooktop, but microwaves are poor at venting.

This is a pretty common layout for many kitchens. As posted, the OTR microwave combination units don't vent as well as a dedicated hood vent. Moreover, for some people, the height is not the ideal location.

However, many people really don't need to have a super powerful hood vent because their cooking styles don't make it necessary. I lived for many years without using my hood and nothing terrible happened to my kitchen. And I did a lot of cooking - but not much deep frying.

Microwave combination units are typically only 30" so you would not install a larger cooktop than 30".

I second getting an induction cooktop in lieu of a standard smooth top because they are so much better both in terms of cooking and in terms of maintenance.

An electric cooktop is a no if you want induction you will still need a venting system maybe post your plan but really OTR MWs are pretty useless for venting.

In March I moved from a house with electric range and decent hood to a house with gas cooktop and OTR microwave. For me losing the hood was far more impacting than gaining gas. And I don’t deep fry or shallow fry, ever.

is damiarain’s suggestion feasible?