I am currently redesigning my kitchen in a 1930's Midwestern USA house. The kitchen has a decent floor area but the floor plan is oddly restrictive.
My space next to the sink is such that I can either have a standard 24" dishwasher next to the sink and a slightly weird cabinet adjacent to it, or I could have an 18 inch dishwasher at 45 degrees flanked by two small but reasonably sized cabinet doors (or drawers), although the 45 degree plan would dictate a somewhat shallow custom counter depth on the flanks (like 18-20 inches).
I think I would be more proud of the accomplishment of building the angled design, and I think the ergonomics would be optimal.
But I'm not sure about the smaller dishwasher. I have never used a smaller one. It seems like it would be enough for my small family and still plenty helpful for gatherings.
I would strongly encourage you to get standard-sized appliances, especially for ones that slot into a specific space like a dishwasher.
We recently needed to buy a new refrigerator. Our opening could not take a standard 36" French door fridge - or must be either a single-door 36" or a French door 33". Neither of those are the current standard. While on the surface there are several models that could work in this space, it quickly became clear that we have virtually no options. Fancy ice maker? Not available. Door-in-door? Nope! Multiple interior layout options? Hah, no!
It turns out that companies only make significant options in the most common size. Thinking that you do not care about those options? I believe that you do not want them now. That may well change in the future, and then you will be stuck. A family's needs change as everyone ages, and the things that feel great now may not be good choices for you later. Flexibility is king when it comes to long term planning.