Follow client's process, or risk blowing up the deal?

Hello there Sales Savages,

TLDR: Share proposal with manager who says they have a process, or hold it back until executive team agrees to join a presentation meeting, at risk of blowing up deal?

Long version:

I'm the founder of a startup that has recently completed a free Proof of Concept phase for a client (10 day trial) on 20% of staff of a 300 person bank.

Our SaaS has generated super powerful insights about Strengths, Weaknesses, Opportunities and Threats for this client. (Our platform focuses on internal feedback from across all employees to figure out how the company can improve)

So far, all collaboration has been synchronised through a division head. On our post trial debrief, he asked us to share the proposal, and also introduced a last minute scope creep (Whitelabel customer feedback, which has never been mentioned till now). I did have a chance to speak to the president twice, and he said his team is in charge of this collaboration.

The proposal requires quite some work, and I don't want to just send it to a black hole without clearly knowing who will decide to buy and presenting our software and results to them.

This is the first big deal for our company and would be a gamechanger.

What would you do?