Things are probably very different now and I suspect there are large chunks of the community that aren't aware of the proposals system at all! I agree with all that you say and I like your "Here's why I support this proposal." idea.

It seems to me that people commonly posted proposals with start dates that were weeks away, and used the intervening time to rally support for their idea.

I could be wrong, but the general community seems to be more "Do now then forget", rather than a slow burn. My expectation is that this is either approved within a month, or forgotten instantly - with a handful of users having the power to decide (or not) its fate.

I'm more hopeful than optimistic 🙂