Should I pay off the mortgage of my Live-In Duplex early

[Kurt Larson]

I own a duplex. Purchased in 2017 for $330k.  Lots of sweat equity was put into this property.  Appreciation since purchase has also been stellar.  Current value $575k.  30 Year mortgage at 2.75%.  Mortgage (All In taxes, insurance included) is $2,500 / month.  First floor tenant pays $2,100 / month.  Owner occupied 2nd unit so my housing costs are very low.   

Should I pay off my mortgage early (one extra payment per year) or should I be happy that I have an asset that appreciated that much and am borrowing that $$ at a historic low lending rate and better use that extra $$ to acquire my next property.  My long term goal is to acquire enough cash flowing properties to retire comfortably.   I feel like the extra payment is not going to change the complexion of my acquiring the next property but still could be a big savings on mortgage interest on the current property.   Is there an easy tool available to compare scenarios?