While it may seem like a simple concept, it's actually a very complex process that requires significant documentation as well as specific methodologies.

@Jonathan Snider another con may include the fact that you will now have multi state nexus and tax liabilities, which often times increases complexity for unaware investors

At one point in time we owned a 24-unit and a 272-unit apartment complex. 

Just because something can be done doesn't mean that you should do it.I would not own real estate within a retirement account(including SDIRA).Reasons1) Complexities with RMD2) Lose out on depreciation3) Appreciation when sold would be taxed at marginal rates instead of preferred long-term capital gain rates4) Etc

We know the housing, cost of living, dependence on tourism complexity and it will be interesting to see how this new attempt to repeal the TVR’s is going to shake out.

By the same token, most GCs who only do new builds can get lost in the much more complex world of full-guts... 

Between 2021/2022 we went from 5 duplexes and a few SFR’s to owning 6 apartment complexes and having 73 units total.Goal 1) to close a contract we have on a 24-unit, bringing us to 97 units.

I was involved as a limited partner in a venture where we bought apartment complexes in Sunbelt, Florida, Texas, North & South Carolina. 

Its my second build at this scope but its exactly the same scope and complexity as what i just finished....just in a much nicer neighborhood so resale is much higher.

Your plan seems viable, but it's advisable to consult with a real estate focused accountant to fully grasp depreciation recapture and the complexities of a 1031 exchange.