Potential advantage of explicit change rules
A clear material-change framework can let ordinary design refinements proceed while reserving renewed review for changes that materially alter public impacts.
Potential risk of approving only a conceptual envelope
If later substitutions can materially change impacts without renewed analysis, the final operating project may differ from what decision-makers and the public originally evaluated.
The verification question
Later major changes should be compared with the approved baseline, including their effects on permits, costs, safeguards, and public commitments.