From their website:
TireJect will seal any tubeless rubber tire. For use in any highway speed vehicle we recommend that the tire is inspected by a certified tire shop to ensure it is safe to drive on. You can use TireJect for bead leaks or short term emergency road-side repair,
There is a safety risk with tires that are not properly inspected to ensure they are safe for highway speeds. For example, if the loss of air pressure is due to a punctured/damaged sidewall the tire runs high risk of failure which could be dangerous while operating at highway speeds.
This is why we recommend that the tire is inspected by a certified tire shop within 24 hours of application.
Additionally, you run the risk of damaging the TPMS sensors that are used in newer vehicles (>2008) especially if tire sealant is left inside the tire for more than 24 hours.
DO NOT apply more than 4oz per tire, doing so could cause tire balance and vibration issues at higher speeds.
Disclaimer:
We do not currently recommend long term use as a permanent repair in any vehicles operating at highway speeds. If you do use it is at your own risk.