The only way to get help with the down payment before closing would be through a HELOC, personal loan, or private lender, as others have mentioned.

One thing you can do right now: create the Furnished Finder listing with unfurnished photos, mention in the description that the property will be furnished soon, and start fielding inquiries and watching the unmatched leads section.

As Account Closed mentioned, the first question is to decide if you want to invest actively or passively. 

Why haven't any of the BP podcasts mentioned this?

I agree with @Michael Baum do guests mention in reviews?

It was mentioned above you could refinance into a conventional loan, however with the 5% down conventional primary residence loan on multifamily now chances are you won't refinance this FHA loan unless you plan on living there for an extended period of time and rates come down. 

You could have it show up under 3 bedrooms when guests are looking for that, but you should mention in your description that it is 2 bedrooms + a loft. 

I only mention this because I noticed your mention of Furnished Finder, which is the only platform I list my MTR, and FF caters to 30+ day stays. 

Reflecting with the beaty of hindsight, I thought it might be worth revisiting some of the strategies mentioned here to explore how they’ve played out over the past year.For example, in early 2023, property values in areas like Bay Park and Clairemont were climbing fast, but they’ve since stabilized a bit.

I advertise the houses that way, even if there's an appliance or two that the previous owner has left in them and I don't mention them so that the people coming aren't (or shouldn't be) expecting to find them.