Some jurisdictions are taking the statewide ADU rules and going much further extreme.  

The rules are as you stated. 45 days to identify up to 3 properties you might buy, 180 days to close.

Hi Michelle, I would check on the rules started by another poster about rules changed for appraisers and basement bedrooms.

There were some carryback rules in the past but not under the current tax regime.

We purchased a property in early October and are placing it in service this week (mid November).We had intended to run a cost segregation study and try to accelerate depreciation which we can deduct against our W2 (assuming material participation).However, we have been reading through the IRS guidelines (eg publication 946 on Property Depreciation) and there seems to be the concept of "short year" which would mean that we can only deduct ~1.5/12 of a year's worth of depreciation in 2024.Is this correct or are there any different rules for STRs specifically?

Using a Self-Directed IRA (SDIRA) allows pre-tax dollars to grow tax-deferred in real estate, but limits flexibility due to IRS rules and potential UBIT on leveraged properties.Investing through a Roth IRA offers tax-free growth and no RMDs, but funding limits and restrictions apply.

Is there any rule or timeline in which this has to be done?  

Also, most deals tend to require a lot of capital ($50K+).Most states exempt business purpose loans from licensing requirements but there are still certain rules/regulations you have to be mindful of.

This works well for me but one thing to note about this process is you absolutely need to know your local and state laws very well so that you don’t break any rules or run the risk of being accused of discrimination, because you will be turning people down and should have a legit, legal reason not just that you don’t like them.

As others have mentioned, there are a lot of rules you will need to follow so please make sure you’re educated.