The nice thing about rehab is you should have a good list of the components. 

They are often classified as operating expenses or maintenance expenses rather than capital improvements (assets).Washer/Dryer/Stove/Refrigerator: These are assets as they are considered durable goods that will benefit the property over an extended period.New Baseboards/Trim, Doors: These are generally considered assets because they enhance the property's value and are not typically replaced frequently.Furnace/AC: These are significant components of the property and are categorized as assets due to their long-term benefit.Paint, Light Fixtures: These can be a bit nuanced.

The final 1031x regulations clarify that nearly all building components identified as five and seven-year property through a cost segregation study are, in fact, real property under Sec. 1031.

A 5 year life span component will have a higher deduction is year 2 than year 5.

Bonus depreciation is just a special part of the US tax code.It allows you to take accelerated depreciation on portions of your property depending on when an asset is put into service.At the time of this writing, you can write off a huge portion (60% in 2024) of many qualified components that have a useful lifespan of 15 years or less.That means a certain percentage of things like landscaping, sidewalks, latches, appliances, fences, certain flooring, etc is depreciable in year 1.The bonus depreciation rate percentage changes yearly depending on the administration and the tax code.For years 2015 through 2017 first-year depreciation for all the items on a 15-year schedule or less was set to 50%.It was scheduled to go down to 40% in 2018 and 30% in 2019 and then 0% in 2020.But then Trump got elected, and he enacted the Tax Cuts and Jobs Act.That moved the bonus depreciation percentage to 100% from 2017 to 2022.In 2023 it went down to 80% and it’s currently at 60%.Depending on who gets elected again, 100% may be back on the table.Only time will tell.We know that the US government wants to incentivize more development and ownership of RE.They want Americans to continue to build and maintain our physical world.That’s why real estate is one of the most tax-advantaged assets in the US.Depreciation and bonus depreciation for RE are very positive and will likely continue in the years ahead.

So, your CPA is correct in saying that the insurance proceeds won't be taxable assuming they were used to repair or replace the damaged portion of the property.Cost Segregation Study (CSS): A CSS is a tax planning tool that allows you to accelerate depreciation deductions by identifying and reclassifying certain components of your property as shorter-lived assets.

Bonus depreciation could be a viable strategy to offset your $300K capital gains, but it typically applies to specific property components identified through a cost segregation study rather than the entire residential property itself.

In the market today you cant simply buy right, the value add component needs to be sizable and in many cases is hidden from the trained eye. 

If you go with a self-directed Solo 401k plan, you can supercharge its Roth component by investing in illiquid assets such as trust deeds and converting them to Roth at a deep discount.

I would expect the same here and I wouldn't be surprised if the industrial components of the Bellweather district outpace the life science components.