I own a couple of US with recharge ports, with a 1.2A charger, but are not wired with a kill key. To date I've not found any other company which does this, and instead only offers recharge ports with a kill key. My main reasons for getting the US sabers without kill keys were mainly because they charge an extra $100 or so for the kill key, but also I thought it would be cool to have a lightsaber room light.
However, as no other company to my knowledge does this, it leaves me thinking there must be a reason why.. Does anybody know of problems that can arise from having ports wired without a kill key, so the saber can be on while charging? At the end of the day, is it not similar to how a laptop charges - lithium ion batteries in the laptop sitting there idly being topped up while the laptop, when plugged in, runs off mains power.