I know! I was thinkin the exact same thing yesterday! Gonna add some weight but I’m ordering one for my A6 as well!!
Although it was my other thread that made me realize it!: List of 18350 flashlights (currently available) - #23 by beam0
“the 18650 tube fits all of them S41/S42/S1/A6”
I also wish they sold the S41S 18350 tube by itself!