Has anyone here successfully managed a portfolio of this size remotely?

Wishing you the best of success!

Now, I have been successfully investing in the San Antonio market since 2019 with 6 rental properties in my portfolio.

This sounds like you have an existing, and I assume, successful practice in place.

What are some usual steps the house hacking community takes to start building a portfolio after the first one is successful?

On the flipside you do have to think even legit successful companies also can't float every job that long.

If you are able to successfully conclude a trade without the use of an intermediary, such as a broker, you of course save the brokers commission.  

My First Multifamily Full Cycle Success Story: From Busy Attorney to Real Estate InvestorI’m thrilled to share the complete journey of my first real estate investment—a 44-unit multifamily property in Lawrence, KS—from acquisition to exit.Balancing a full-time legal career and fatherhood, real estate seemed like an impossible dream.

Once you have a few successful deals under your belt, you can explore leveraging options like hard money to scale your portfolio more aggressively.Good luck with your investment journey!

I believe the  key to success are the constant reminders to tenants to conserve water (and thus, save money)