Two observations from my impressions about the proposals of previous years. Basically, there's a political aspect to the system (assuming that the top-tier stakeholders are willing to consider SPS proposals at all, which is still an open question from my vantage point).
In general, community advocacy was helpful for getting proposals voted above the return proposal. Sometimes, (usually?) it was not enough to just post the proposal and watch it get voted up. Some cheerleading/persuasion was often involved. 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.
Once a proposal goes above the return proposal, something to be prepared for is that it might float above and below it a few times at during the lifetime of the project. No idea if that would still happen in today's Steem ecosystem, but it's a possibility. If a large stakeholder votes for your proposal and also the return proposal, that leaves room for smaller voters to tip the scales.
If any of your audience supports this idea, now might be a good time for a bunch of posts about "Here's why I support this proposal." 😄 Not sure if I'll have time before your start date, but I might try to write one this weekend.
Good luck. Your proposal definitely has my vote!
RE: Modernise steemit.com Interface (DAO Proposal)