I have 5% of my paycheck going into an investment account at fidelity and every time I have XXX amount of surplus dollars after bills are paid I send this money to my Fidelity investment account.I am looking at acquiring another property and feel like I can improve my system.

Once those pre-approval amounts get lowered, we will see an inventory surplus , which will lead to price cutting. 

My goal is to be financially independent by the age 35.My question is what to do with my surplus of income to reach my goal?

But there is/was a housing shortage, not a surplus.

or, to look at it another way, what would a "surplus" of $7,200 a year in gross income do to the value of your property?

Conversely, if the property were to sell for more than the outstanding debt, the mortgagor/borrow would retain the surplus. 

You have to spend less than you earn to have surplus money to invest.  

Lol , Brazil has very strong trade surplus recently :) and Mexico too…..they are growing faster than United States.

All my tenants were very happy with the announcement Governor Newsom is sending them each $600 extra in stimulus From the California budget surplus and landlords can now collect 100% of a tenant's past due rent for not evicting people during the pandemic.

We have a surplus of off-market homes that go at a discount.