Awhile back I was watching a video series/course @Brandon Turner had done and was on the site...it was pretty comprehensive and saved your progress.

If the partners agree to specially allocate one item (for example, capital gains) 80/20 for economic purposes per SEE safe harbor, the corresponding tax amounts must also be allocated 80/20.However, IRS has a framework that can reallocate the partnership items based on the “ partner's interest in the partnership” if IRS determines the method of sharing the partnership items lacks the “Substantial Economic effect” (SEE) To meet the SEE, there are strict rules to maintain meaningful capital accounts including Deficit Makeup Requirement for those accounts.With the requirement, the partner must at some point contribute sufficient capital to eliminate the deficit, and the partner has the burden of the loss that partnership has and the allocation of the partnership will be respected by the IRS.This is a very high-level summary of the rules and is not comprehensive. there are many exceptions as well.Since the substantial economic effect, safe harbor allocation rules are complex and requires considerable additional recordkeeping, it's easier to follow PIP standard. 

Your way around it if it is fix and flip is to just do work that will increase the appraisal: improve curb appeal, enhance the kitchen or bath, or turn it into an open concept.

@Michael Frankel two great and comprehensive resources I use are learnairbnb.com and getpaidforyourpad.com.

I think that rep probably is because many people try to get their start in RE by wholesaling and don't have a comprehensive understanding of how a rehab works or how much it costs.

Right now, I'm doing some in-depth research on each city - looking at their Comprehensive Annual Financial Report, checking out the population, job market, who's landlord-friendly, etc. 

One must develop a comprehensive discipline for analysis and negotiations to help ensure their success in this niche. 

But w/ my fairly comprehensive spreadsheet, I'm making around 12-13% ROI.

I have been trying to compile the most comprehensive commercial due diligence for each side, seller & buyer, and have a lot of information to be thorough yet efficient.

While I do not agree with all of his strategies this is by far the most comprehensive book on hard money lending I have ever read.