In truth, what really bothers me here is the imbalance of technology the firearms will create, it creates situations where some parts of the map are just ready to enjoy the fruits of the industrial revolution whilst the others are stuck on medieval roleplay thus crashing any immersion that exists in the world.
What was described in the thread was a Flintlock musket, if firearms are to be added, I suggest they'd start off with crappy, prone to malfunction and 15 or higher roll to hit Matchlock Arquebuses that require multiple emotes to engage an enemy with and a lot of IRP training beforehand. After given a lot of OOC time, the Matchlock firearms can gradually evolve overtime to better to use Muskets, but really, it's a very risky thing to implement and I see no thoughtful or important reason to implement it at this time.