I recently had an estimate of $20,000 to create a basement egress window and I put my foot down and told my GC that I was going to rent the excavator, and we found much cheaper supplies, and were doing the project ourselves.

It is not too expensive and it is cheaper for guest to book direct and you make more.

Also with inflation you pay with cheaper dollars.7.  

Apparently they should be brick pointing with lime mortar, but instead, they said the city will just plaster over the historical materials (original brick and lime mortar) with Portland cement because it's cheaper, faster and easier than working with more delicate, temperature sensitive lime mortar. 

Allowing you to borrow money at a cheaper cost.

Ideally I'd like to have the corporation pay expenses directly or it will look like income if it is transfered to me or some kind of expense reimbursement both of which would be taxable personally. 

It’s a great way to lower your taxable income and improve cash flow.4.Dividend-Paying Stocks/Covered Calls: If you’re still leaning toward investing in the stock market, dividend-paying stocks or using covered calls could provide steady income while reducing risk.5.DSCR Loans: You’re already on the right track with DSCR loans—a great option to keep scaling your portfolio without relying on W2 income.Hope this helps give you a few more ideas!

For something like an ADU it's surely going to be cost prohibitive.If you want to buy a cheaper property with your 1031 that has the ability to put an ADU on the lot. 

Smaller properties are cheaper to update or can use higher quality materials.

Keeping their taxable income down is a huge advantage for you as paying that from the sale would not be the most fun, although maybe I am incorrect since the property was inherited.