I've had this happen with multiple units of apartment buildings.

To increase cashflow to move into a STR situation, which then has tax benefits, yes. 

Consulting with a local real estate advisor or financial planner can provide personalized insights based on your specific situation. 

Hi @Shawn Ta A lot to go over in this, honestly tough to say without know more about your situation and comfort level. 

I’ve read through multiple posts of people asking about a HELOC on a seller financed property, but what I’m wondering is if anyone has done so on a home purchased “Subject To” the existing  note?  

Are there any guidelines for situations like this where the tenants would need to stay somewhere else while the renovation is in process?

I would need to know more about your situation, but you need to be wary here of depreciation recapture.

If you are NOT in a negative cash flow situation I would definitely keep it for the rest of your life. 

I'm pretty sure it's the first, but just want to make sure because I've heard multiple people word it the way you did and just want to make sure my understanding is correct.

That is what a chapt 13 is all about.I must be missing something you are trying to say . . .Even in a chapt 7 it doesn't always go to sale and the debtor can save the situation.