@Jamie Wheeler All us insurance guys are going to tell you that if you want to have your investment protected (including the gains you make both in renovations and through appreciation and inflation) then you need to be insuring your properties for Replacement Cost.
There are tons of REI that only insure for Actual Cash Value and have never had an issue. Thus in those Investors eyes they have been saving money on their balance sheets every year. I am both and have experienced a loss where I was only insured for ACV and a loss where I was insured for RCV.
The claim where I was covered with ACV was an absolute nightmare, I fought with the insurance company for almost every dime they paid out, and I still ended up coming out of pocket for over $15,000 to repair the property.
The claim where I was covered with RCV, the day after I made the claim I had a check from the insurance company for the full amount of the estimate that the remediation company estimated. Then when we got 2/3 done with the repair we realized we were going to need more money and the insurance company wrote us another check with no issues.
Plus after the repair on the property with RCV we got a new appraisal and that came back way higher than what the property was worth before. (disclaimer this is not always the case and cant be guaranteed you will have the same growth) But your property will be built back to at least the same as it was before
The question that you need to answer for yourself and don't let others persuade you as to what you should do because that is what they would do. But the question that you need to answer is- WHAT IS YOUR TOLERANCE FOR RISK?