Isn't it dangerous if the transaction signal queue can trigger the gas to overflow and become a fire? unless previously ordered with the application system in advance.
If this system is created, there will be a safer way to pay and this will probably be paying in advance.
if they don't use stable coins, many will be confused by the ever changing rates.
To solve this, at least they can create stablecoin.
So, IMO the problems you said are like trying to stop someone who wants to set up this system. The problems are not too big to be solved.