So... Bottles!
@Train2,@SteamStack, @CMD-Ky, @kross8, @oplholik and anyone else who might be interested(apologies if I left anyone out) - these are the bottles I've been looking into. They fit the 18490 and the 14500 as well. Only 5ml, but at least that's 2 extra in the minis. It is a little...