There appear to be some new startups offering to pay up to 50% of the down payment on a house in exchange for around 35% stake in the house (they collect this upon sale).

Boxabl acknowledges SEC inquiry in updated filing | Business Insider India its a double whammy start up and trying to sell in a very tough interest rate environment. along with inflation and cost of components to the point their 50k to 60k box probably cost them quite a bit more to produce than what they were going to sell it for. 

For example, it's not uncommon to see a whole Asian family live together for a long time and essentially using group economics to start up family run businesses.

I recall a specific framework of business start up along the lines of starting with yourself, then adding an Admin, then an Ops, and then other support functions after that. 

If you put it out there asking for a 3-5 year lease with a small business or startup in your mind, but H&R Block or Supercuts comes along asking for a 10 year NNN (& it's corporate) and agrees to the rent amount you requested, there's no reason not to entertain that, you got better than what you were expecting (there's a reason NNN properties, or ones with a few NNN tenants sprinkled in that are national chains, often sell for lower cap rates), it's not like taxes or hair cuts are going obsolete any time soon. 

Assuming you are using an LLC or S corp will pass thru income you would just have to show how you personally loaned the business money for start up or operating expenses. 

Passion, dedication and grit is what makes a start-up successful, not the hunt for $$$$. 

The startup then took a referral fee from its users’ returns when they were sold.

Besides it being much slower start up to self-fund, why not use cash instead of financing to avoid the risk? 

Are they going to start up the next fun side project or fund?