Add signal, not pressure
A useful follow-up gives the client one more reason to respond. That could be a sharper scope question, a risk you noticed, or a small implementation suggestion.
Repeating the original proposal reads like automation. Add context only if it helps the buyer make a decision.
Save snippets, then personalize
Keep two or three reusable follow-up structures, but customize the concrete detail for the job. The reusable part is the shape, not the substance.
Use follow-ups only after real proposal sends so your tracking reflects actual pipeline behavior.