I think the only Toyota type vehicle that Toyota says can be flat towed is one of their 4Runner models. We have a 2014 Toyota FJ that Toyota offers no means to modify it for flat towing. They say, do not lfat tow.
The FJ has an automatic tranny with a manual transfer case (2H, Neutral, 4L, 4H).
I installed the Remco driveshaft disconnect kit and have towed ~10k miles so far without problems.
I leave the transfer case in 2H, pull the knob to disconnect the driveshaft from the differential.
The big deal here is the manual transfer case. The only way to disconnect the front axles is to leave the transfer case in 2H. Any other selection connects the front axel, including neutral. Weird huh....
If you have an AWD, or full time 4WD there is no way to manually disconnect the front axel.
This is just my experience. Not recommending anyone do this. Be sure of what you are doing to keep everything glued together.
Phil