Why does sales visibility stop the moment a proposal gets sent?

We spend a huge amount of time tracking what happens before a proposal goes out:

• Lead scoring
• CRM activity
• Intent signals
• Opportunity stages

But once a proposal lands with a prospect, most of the visibility disappears.

The rep knows it was sent.

Maybe they see an open notification.

But they don't know:

• Who actually read it
• Whether it was forwarded internally
• Whether multiple stakeholders are reviewing it
• Whether the buyer is moving forward or quietly losing interest

I'm exploring this problem through a product called DocMetrics.

Curious:

How do your teams determine whether a proposal is gaining momentum or dying after it's been sent?

Are there signals you're already using that I'm missing?