"Lithium Batteries" should be treated as a generic term. There is at this time several different chemistries in use. Some, obviously, less than perfect.

Lithium-Iron is one that is now being used for large battery banks in RV's for example, with good success. Unfortunately unless the manufacturer explicitly says what chemistry is being used it is difficult to know.
In this case, with only occasional use and the battery itself wrapped in a sealed case I am not concerned. I am always careful to charge lithium batteries where there is lots of air movement around them.
It should be remembered that jump starting a lead-acid battery is itself a dangerous activity. And based on my personal experience, lead-acid is far, far more dangerous than lithium. I've been burned twice by exploding lead-acid batteries. The difference is that lithium is used in myriad small devices that we all consider 'safe' and lead-acid is used in car engine compartments where we know 'dangerous' things live. So when a lithium battery goes bad it is front page news, but when a lead-acid one explodes it rates not even a mention.