Having ACV on roofs 10-15 years old is very close to being the new normal with many companies with others going to a percentage deductible for wind or hail damage 

In my most recent deal with a partner, I bought the land (10k), he pays all costs, I build it, he's building it cash, I put my fee into the deal and that was given dollar for dollar value. it's all based on dollars. so 10k, 25k GC fee on this 720 sq ft affordable house we are doing, plus my realtor fee so my basis is 41k and his is the cash to build which is probably 80k. so I get equity of my percentage contribution. shouldn't be too tough and that's super fair in my opinion. we build at cost when we use a retainer based model and I'm not extending any credit to the borrower. 

If they get a percentage of the monthly cash flow, won't that cut too much into my profit?

- What percentage of deals have gone full cycle?

The HEI/HEA is not feasible because of the percentages most companies are wanting to take (some are over 50% of the appreciation from the date of the HEA).The biggest question is that we'd be losing our 2.875% rate, which will be paid off in 15 yrs.

There will be no way to finance at high percentage of what is owed due to in effect buying the sub to position.  

at its most basic titling the TIC, does not require equal contributions it's just a deed defining percentages.

Many national STR PM companies working on a percentage of gross income (Daily rates + cleaning fees) charge an elevated cleaning fee.

Let’s say they provided it for 100% free retail Buyer profits in exchange for a percentage of your profit.  

Yes, probably 50/50 to start and then once you have a strong track record with them, you may have the leverage to try to get a higher percentage on your end since technically what you're doing is more time intensive than what they are doing (cutting a check).