Dual citizenship: two passports - same name?

So, dual UK-US citizen., living in UK:  im thinking of renewing my US passport, non urgently, for a holiday in '24 or '25/.

My last US passport expired 20+ years ago

I was John Smith then.

Since then I got married , changed my name  to  John Wifename-Smith , then got divorced.  I never bothered to inform the USA.

My UK passport and driving licence are John Wifename-Smith , because I am too lazy to change them back. 

My US old US passports are John Smith

Id like my new US passport to be John Smith

so:
Is the US embassy going to care that I changed my UK name but not my US name.

Is it going to cause a world of pain if I travel to the US and my passports dont match. 

I have never been asked to show my UK passport when visiting the USA, except to the airline when returning to the UK to prove I have the right to enter, but my name is the same on both.

I can't recall when renewing my US passport if I have had to show my UK passport as well. Certainly when renewing my UK passport I have had to send a copy my US passport.  Renewing your US passport might be more problematic than traveling on it.

The 20 year lapse might be problematic, may not be able to do so via mail.

https://uk.usembassy.gov/u-s-citizen-services/u-s-passports/renew-an-adult-passport/

Eligibility
You may renew by mail if all of the following applies:

Your passport is:

Undamaged;
Issued within the last 15 years;
Issued with a 10 year validity; and
Issued in your current name or you have changed your name and can submit legal documentation to prove this change.

My UK passport and driving licence are John Wifename-Smith , because I am too lazy to change them back. 

My US old US passports are John Smith

Id like my new US passport to be John Smith

so:
Is the US embassy going to care that I changed my UK name but not my US name.

Is it going to cause a world of pain if I travel to the US and my passports dont match. 

The British government won't like it because your foreign (in this case US) passport must be the same name as your British passport.
https://www.gov.uk/government/publications/names-aligning-names-on-foreign-documents/names-aligning-names-on-foreign-documents-accessible#Customer_refuses_to