Keyboard backlight setting does/doesn't include "Never"

I've got a e6420 and swapped in a backlighted keyboard a while ago and it does work, but I want it to stay always-on so I installed the Feature Enhancement Pack (2.2.1) and I see the various options (Turn off backlight in 5 seconds, 15 seconds, etc) but - and this is where I've not really seen an explanation for this - some examples show the option for "Never" (ie never turn off) and some don't show the never option. Does the presence or absence of the "never" option depend on the version of the Feature Enhancement Pack, or the particular model laptop, or something else? Also - from what I've read - even when you have the "Never" option, that it sometimes (or frequently, or always?) does not actually work as intended?