Given a parameter like this:

        - name: foo
          in: query
          style: deepObject
          schema:
            type: object
            properties:
              min:
                type: integer
                format: int64
              max:
                type: integer
                format: int64

The generated client code:

1. Marshals the struct to JSON
2. Parses the JSON back as a map[string]any, resulting in the numbers being converted to float64 -- already not great her I think
3. Constructs the query parameter values using fmt.Sprintf("=%v, ...) resulting in the integer parameter using floating point "e" notation if it's greater than ~ 100000
4. The generated server then refuses to parse values like 1.23454678e9 as not valid string representations of integers

Item 2 happens in MarshalDeepObject:

Item 3 happens just above in marshalDeepObject:

I think that, if it has to go through the unfortunate JSON loop, it should use a json.Decoder with UseNumber() applied so that numbers are retained at full fidelity. This is what styleStruct does for other styles: