If we bought a house as a vacation rental with the 10% down and then later decided to change it to a LTR, how would that affect our loan and what would we need to do so to not unintentionally create a mortgage fraud?

Unintentionally of course, but still... 

Specifically, the following issues are often examined:Purpose for which the original acquisition was madeDuration of ownership and the purpose for which it was soldFrequency and continuity of salesThe extent to which improvements (if any) were made to the propertyControl and effort expended by the taxpayer in the sales processUse of real estate brokers and extent of advertising initiativesOrdinary business and experience of the taxpayerNature of the taxpayer’s other real estate holdingsIncome from the sale compared to other sources of income and employmentReluctance or desire to dispose of the propertySo considering the above criteria, one could look to see if the flip was intentional or unintentional. 

(The VAST majority of agents/brokers working residential real estate are Realtors)Fiduciary DutiesA real estate broker who becomes an agent of a seller or buyer, either intentionally through the execution ofa written agreement, or unintentionally by a course of conduct, will be deemed to be a fiduciary.

You could possibly be steering them in the process (unintentionally) to a property that might not be best for them but is better for you ownership wise.No legal advice given.    

@Jeremy Pace you're either intentionally or unintentionally not understanding escalator clauses.  

Or, if you fail to properly maintain some aspect of your property (even unintentionally!) 

Don't go by the wholesaler's estimated rehab cost, he might be well intentioned, but do your own numbers and double check the property for anything he might have "unintentionally" left out.

I have faith that our system of laws is fair and the most punitive sections of the code are  for those who are trying to take advantage of system, not those who make  unintentional mistakes.  

I decided to refinance my house and pull out the equity which was an unintentional BRRR strategy.