In my past experience in TX RE purchasing lots or vacant land from taxing entities and sitting on them until the right of redemption passes turned out well for me with few issues. I never tried it with improved RE.
As I recall title companies are hesitant to insure title on tax sale RE until the right of redemption passes. If you plan to flip, that could impact the ability for your buyer to obtain financing. Although there is interest compensation for a tax sale redemption, it might not cover the time and energy you’d invest in a rehab.
I’m sure some experts have ways to get around these hurdles, but I’d recommend talking to them and a title expert before sinking a ton of money into this.
There are also some pieces of RE out there you don’t want to own because of all sorts of issues (access, title problems, environmental, ETC). Those frequently end up on the delinquent tax list and stay there forever!
If you are starting out, there are so many more easier ways to invest in RE today than there were 10-15 yrs. ago.
AirBnB, house hacking, crowd funding and a ton more I’ve heard about on the GP Podcast. None of these were around when I started.
Bottom line, I’m not a TX tax sale RE expert, but I believe it is not as simple as it is in some other states. So I’d find a TX mentor and learn the ropes before diving in.