Kitchen fitting with out of plumb walls

[Captain Nemesis]

Can’t see any mention of a professional kitchen fitter or any evidence of one in the photo.You make a lot of assumptions.

Yes.

I was assuming that

we are having a kitchen fitted, all bespoke.

meant that the OP did not pay for a bespoke kitchen to be made and then got an amateur to install it FOC.

Now that I think about it again I realise
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how
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reasonable an assumption it was....

 

[foxhole]

Yes.

I was assuming that meant that the OP did not pay for a bespoke kitchen to be made and then got an amateur to install it FOC.

Now that I think about it again I realise
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how
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reasonable an assumption it was....

People often use Bespoke without understanding its meaning.

 

[Deleted member 174758]

...neither are truly level, how would he go about making the gap uniform along the edge without compromising something further down the line?

You don't/can't. The units must have plumb ends, the tops must be level front to back and side to side, ideally checked with a long spirit level end to end of the units as well (this highlights any minor sag in the tops of the cabs far better than any laser line can - a string line can do the same but TBH is a bit of a faff to use in kitchens). If the walls are out then your scribe strips should cover this. You cannot line up the units with the walls, but you can overboard/dot and dab with boards to correct wonky wall make it line up to the kitchen (something I have found necessary on a few occasions). A professional fitter should know this...