The difference is a 3 family requires fire escapes and a concrete enclosed furnace room.

Just like fitness (my day job) while all the information is available and out there, the key is having people take action and do the required work.  

But if you to a more wise and slow approach, you can find other ways to generate additional income, build up a 25% DP on a duplex that cash flows after all expenses and you have an EF fund, well you will sleep better at night and the odds that your investment will survive the tough times in your life is far greater then someone who sleep well at night with tons of debt who if anything should go wrong, which it does in life that person may be bankrupt. 

Managing the $73,000 renovation budget required careful oversight to stay within financial limits and meet deadlines.

But at that price point , that will be fairly minor.Once you hold the hard money loans for the seasoning period the portfolio lender requires, just roll over into that.

The primary determinant (beyond the tax implications) is whether the lender will underwrite and permit the borrower to close in a company or require the individuals to be reflected on title. 

@Joseph Chiofalo  The properties that have conventional loans are in personal names (can't hold them in LLC and be compliant with Fannie/Freddie requirements to be best of my knowledge).  

The way I've valued multifamily properties is to calculate the Net Operating Income (Gross Income - Expenses) and then divide by desired cap rate.  

@Peter W.The question that changed my life was Are you working hard for your money or is your money working hard for you.Making more income does require time, but does the average person have their money working hard.

I am not sure how the owner occupancy requirement of the JADU impacts value, but is will impact value as there are many RE investors who do not want to owner occupy.You should be able to determine the value by calculating NOI and knowing the market cap rate.