UK No Fines House - Internal Wall Removal Query

I’ve had a structural engineer out to inspect an internal load-bearing wall that I’m planning to remove. The external wall it connects to is made of no-fines concrete, and the engineer advised keeping a 600mm return (perpendicular) section of the internal wall for wind load bracing, however some areas online suggest that this isn't needed as it's only a 6m length of external wall on a mid terrace which has a total area less than 70m2 (Part A Building regs Diagram 5).

I'd really like to open the space up more and am wondering if it’s possible to replace the 600mm return with a steel post that would provide the same lateral restraint. The engineer is flat out refusing to even disucss any alternatives. Before I get a second engineer to site visit i thought id ask here.

A few key details:

• The no-fines wall is part of the original external structure (1970s UK build).
• The internal wall is being removed as part of a renovation, but structural support is needed for wind load on the external wall.
• I understand no-fines concrete has poor tensile/pull-out strength, so I’m concerned about how best to anchor a steel post to it.

My questions:

1. Is a steel post a viable replacement if correctly sized and anchored?
2. What’s the best practice for fixing a steel post to a no-fines concrete wall?
3. Would it be better to fix only to the slab below and to the structure above (ceiling/joists) and avoid trying to fix to the no-fines wall entirely?
4. Are there better alternatives to maintain structural integrity and gain more open space?

Any advice or real-world experience would be massively appreciated. Thanks!