I have heard vented units don't dry as effectively but haven't heard any complaints from my tenants and believe the technology continues to improve.

Looking into my crystal ball - which I still keep in my closet from my previous life on Capitol Hill - neither of these risks have a realistic path to a meaningful economic effect.

The only approach I’ve found effective is offering a deposit alternative, which lowers upfront costs for tenants without devaluing your property.

Take a look at BP's blog where new articles are published every day: https://www.biggerpockets.com/blog4.

https://www.biggerpockets.com/...12 Frequently Asked Questions (And Answers) About DSCR Loanshttps://www.biggerpockets.com/...8 More Commonly Asked Questions and Answers to DSCR Loanshttps://www.biggerpockets.com/blog/eight-questions-and-answe...What Documents Do You Need for a DSCR Loan?

Again, the BiggerPockets store has some books on this topic, or you can learn about it by watching podcasts, reading blogs, and interacting on the forum.

Less Desirable Areas: Are there neighborhoods we should avoid or areas where BRRRR might be less effective?

We do have a property management company and even with our experience with LTR's, just no way we could effectively manage this home without local property management. 

With those, the HOA fee's usually have a big negative effect on cash flow. 

Quote from @Rene Hosman: @Austin Wolff recently went through this process of identifying markets to purchase in and he goes over his thought process in this episode on the Rookie podcast about how he used the MarketFinder here on BiggerPockets to find markets that met his criteria Podcast: https://www.biggerpockets.com/blog/rookie-473MarketFinder: https://www.biggerpockets.com/marketsI specifically only focused on 2 markets (Indianapolis and Fayetteville, AR) before I found a deal using the BP "deal finder."