No trust me then you see how ineven your ceilings are.

Not worthwhile for the several reasons that @User noted.

As an aside, @Illie's point is not really correct. A contractor with experience will know how to scribe the crown molding so that it meets the uneven ceiling perfectly and the uneven ceiling is not noticeable. This should be Carpentry 101, that apprentices learn the first year, but it is surprising how many contractors either don't know how to scribe crown molding to the ceiling, or don't feel like doing it.

I agree in that the right contractor can make any ceiling look even, but as we see on this forum all the time, that is not always the case. I also had a contractor that promised to scribe the crown to the ceiling and the uneveness would not be noticable but our standards were not the same. He thought he did a great job and refused to admit otherwise and I have had to look at my uneven ceilings which were made more prominent by my full height cabinets for the past 3 years everyday regretting them.

OP your cabinets look beautiful. Don’t spend extra money on something that may bring more issues unless you really want stacked cabinets and have the money and resources to get the look you want.

I wish I would not have listened to all the advice on here on taking my cabinets to ceiling because it would make the space look bigger or to prevent cleaning the tops.

I have never figured out why anyone wants those to the ceiling cabinets anyway. They are too darn high to be any good for anything. I already need a ladder to access the top shelf in my shorter ones.