On the question of safety, yes it is safe for a few reasons. One is that CO2 is not a real hazard unless we set up some really weird situation where we fill the room and can't get O2. We do breathe out CO2!
Second is that the tank has built in safety limits and will vent off pressure if it gets really too high so that the tank might split and that limit is way high like beyond 1500 PSI or more.
CO2 tanks are very bear bullet proof if we don't let them tip over to knock the top off, which is a super danger! Consider that folks use CO2 in bars, hamburger joints or anyplace that sells soda or beer. They are used by welders who often throw them in the back of a truck or van and leave them on the roof of buildings in the sun all day.
Bigger hazard is to your wallet as the heat does tend to dry any lube on the solenoid moving parts and distort the parts just enough to make them stick on or off.
If the new folks at Burger King can't figure out a way to blow it up, you are likely to be safe?