Direct driving XM-L2 from 10440?

I'm attempting my first flashlight mod of a Maglite Solitaire to install either an XM-L2 or a Nichia 219 emitter. (Have both, haven't decided which to run)

My concern was that the video I watched describing this mod showed a Nichia 219 emitter wired straight to a 10440 battery, which made me concerned. Without limiting the current in any way, won't the LED pull too much and burn itself out? Are there safety concerns running a 10440 battery in this manner?

I haven't looked into the datasheets for the LEDs yet, I was hoping there was standard practice the other modders used.

I haven't experimented with direct driving the 219 but after looking at the discharge graphs of 10440 cells and the forward voltage vs current graphs for the Nichia emitter it doesn't look too scary -at least compared to the XM-L2. Hopefully someone with hands on experience with this combo will chime in.

You can direct drive an XM-L2 with no problems to the LED, you will never reach a current that is high enough to damage the LED. The XM-L2 has a pretty high Vf (3.6v @ 4A), which you will never reach with a 10440 cell. Even when IMR and fresh of the charger. The Nichia probably is OK for the same reason.

Wether the cell is up to the job is a bigger question. When it is a IMR cell, fine. But when it is a normal LiCo cell, it might be not wise and you should limit the current somehow.