Return the document, don't rebuild it
The proposal goes out on a template signed off by the communications team. It comes back reformatted, and someone loses a day to it. That is not a technical inevitability.
Why formatting gets lost
A Word file is not text. It is an archive holding several XML parts, the images, the embedded fonts, the styles, the numbering, and the relationships tying all of that together. When a tool "generates a document", it usually builds a brand-new file from the text it extracted, then tries to reapply an appearance on top.
Anything not explicitly rebuilt disappears along the way: an inherited style, a conditional footer, a diagram's anchoring, numbering that restarts from zero. The document resembles yours without being a copy of it. The gap shows exactly where your brand rules are most specific, which is exactly where the communications team will look first.
Diagrams are the sorest point, because they do not degrade quietly. They vanish, or they come back at the wrong scale.
The inverse approach: don't touch what hasn't changed
There is another way to do this, and it comes down to one rule. Sections you have not modified are not regenerated. They come back as your file's original bytes, meaning an identical XML clone, images and tables included.
So the brand is not re-rendered and then repaired. It survives because those parts of the document were never opened. Only the sections you actually changed get rewritten, and those are the only ones to review.
- Styles, footers and numbering in unchanged sections: those of the original file, byte for byte.
- Images and diagrams in unchanged sections: no re-encoding.
- Replaced media: added as a new part, rather than written over the existing one.
What this changes about the schedule
Reformatting almost always lands at the worst point in the schedule: the day before submission, when nobody has any slack left. It is also when layout errors go unnoticed, because review at that stage is about substance.
Removing that step does not tick a box on a project plan. It takes an incompressible task out of the one day when the bid can no longer absorb a single surprise.
Ask to see what the tool returns on your own template, with your own diagrams, before you commit. The question is not whether it generates text, but what it does with the parts you never touched.