2nd Gen(2014 i4 2WD ) ECU Flashing

Before I start spouting off questions I should probably explain my background and why the hell i'm trying to do this: I come from a Network Penetration Testing / Ethical Hacking background. I like to tinker with things and I want to fart around with my truck.

I'm not too well versed when it comes to engine tuning or cars in general, but it still peaked my interest and i'd like to go about it anyways. After Googling around for a couple hours I came across this blog post: https://www.alientech-news.com/en/k-suite-3-19/ It shows that you can rip data off of the Toyota Denso ECU that is in my truck (DENSO 89661-04J21) and throw data back onto it.

I'm assuming I can edit the data pulled off of the ECU with another piece of software and flash it back onto the ECU ROM chip correct? Am I missing any security measures Toyota has thrown into place? All I know is it makes sure the hash of the file you've flashed is the same but that's about all i've come across at this point.

I'm aware modern Toyota ECUs are pretty locked down but I thought this'd be the best place to ask.