If the company is not interested on listening to new ideas, and you're keen on participating in something you would like to help build, then perhaps this is not the right company for you.
Just please be aware that after you've delivered, you loose power for negotiation. Therefore I would probably rethink the timeline choosen for agreeing on a reward "then I can say how much I want to be compensated for..".
But only if you think it will demonstrate enough value to get you something you desire: cool work, a promotion, etc.
This requires a good understanding of what your managers and the larger organization will value, and whether they reward people who show they can deliver on those items. People's careers _do_ get bumped from these kinds of efforts, but I've seen a lot of engineers spend 40 hours prototyping something that management just won't value.