This section constructs a with expression containing multiple where/new value pairs -

However the API here only provides access to a single where/new value pair -

What should be the preferred way to deal with this mismatch?
A. Update the lowering to nest with expressions rather than constructing a single expression with multiple pairs.
B. Update with_exprt to expose the possibility of multiple pairs.
C. Work around the mismatch for the moment using exprt::operands to access the additional pairs.
I am not a huge fan of option C as it leaves the possibility of multiple pairs relatively surprising when referring to with_exprt. Option A seems relatively preferable as it keeps the API simpler, however I have also presented option B in case there are performance reasons for preferring more operands over more deeply nested expressions.