I'm always game to chat real estate.

To win the STR game, especially if you're a new entrant, the most important aspects are 1) Amenities2) Location3) Property type4) UniquenessAll are geared toward you standing out on Airbnb/VRBOHot tubs, fire pit, bowling alley, pools etc. or being in the best location in an area as well as being to host a large group are all things to help you win.

From what I’ve learned, focusing on properties with under-market rents can be a game-changer.

That’s a game-changer when it comes to flipping profits.Your scenario reminds me of a client I worked with in San Diego who flipped a condo after living there for a couple of years.

You can only play games for so long.Chances are your next door neighbor is an IRS agent and turns you in when your tenants blocks their drive or some other random event disturbing your IRS neighbor.ADU catches fire and your insurance won't cover you, because it was an illegal and unpermitted structure.The city inspector told the last guy not to build or rent it, and is now pissed and wants to make an example of you and just red tags the whole property and no one can occupy for the next 1-2-3 years while you wait for a hearing.Then when you get the hearing, "staff" recommends you tear the whole structure down, and if you still want an ADU, you can apply for a permit and rebuild it.Your tenant quits paying rent and won't move out and you can't evict them, because there is no valid lease and they're just your "roommate".Probably a dozen other bad things can happen to you when you do stuff like this. 

In the end, you have 2 choices when there is a change, blame the system or find a way to win the game.

Unfortunately most lack the balance sheet to obtain favorable financing, can't afford to put any skin in the game and fail to make a compelling reason for why the investment makes sense or to justify the structure they are seeking.

Selling "Golden Tickets" has proven a dangerous game for many through-out REI history.

It’s a long game so worrying about the short term is kind of pointless.

Person new to real estate trying to get in the “game” with little or no capital and trying creatively.