Agree with @Autumn1990 you need to focus on finding a good fitter. It's easier said than done but maybe try dreaded Next door and local what's app group I found these were good places for this.
We saw about 5 and all of them did that irritating teeth sucking/ face pulling thing about the walls.
Last guy we saw (and used) was like "hmmm.... Interesting problem. Okay here are some ways we could make work".
This is what you want. We had numerous things come up in the renovation and I could work with him and have sensible conversations.
He would say yes you can do that but it will mean X is that okay? Or we can do it this way? Positives are this but downside is that.
This the problem, we can solve by doing A or B. What do you think?
By the way the boarding and plaster work cost me an extra few hundred. This was summer 22 in London. It was a last minute add on.
The other thought I had was that might be worth talking to a kitchen designer like Karen at one plan (Google it MN is semi obsessed) she focuses on your lifestyle and needs and may be able to help you get clarity on custom Vs standard
My final boring bit of standard kitchen advice is fit 2 more plug sockets than you think you need on the counter and install a usb plug in your "bits and bobs" kitchen cupboard so phones can be charged out of sight.