SF 6PLED + A19 = brighter? More Runtime?

I am looking for a good emergency light for my better half to keep at her office. I decided on the new SF 6PLED. It is doubtful that she will need more than 80 Lumens, and this light will give her 11 hours runtime without getting too hot and shutting down.
To improve on this I am considering adding a A19 adapter. In theory this will add to the runtime, and possibly add to the Lumen output. Has anyone done this? You would effectively have a 9PLED. What is good or bad about this thought?
I am not really looking for added Lumens since this might make the light run hotter and eventually too hot to comfortably handle. The added runtime would be a bonus as it would mean changing batteries less often.
In this scenario the size increase between the 6p to the 9p would not be a big factor. Has anyone done a runtime test with three cells? I would be using primaries (CR123) for this setup since they have a 10 year shelf life. Thanks in advance for the input...

Hmmm...digging through the threads and it seems that the 11hr runtime advertised by SF is not very accurate if you want to stay above 60-80 Lumens. So with a 2 cell bdoy you are looking at a battery change about every three hours...any one know about 3 or 4 cell? Might run this head on my 9P+A19. Too much voltage for the LED??

9P + A19 + LED from 6PL seems to be the ticket. Running well and not getting too hot. Should be in the 5-6hr rnage of 60-80 Lumens. Not noticebly brighter so that must be controlled for a maz of the 80 Lumens SF advertises.