I do not see the Ello Mini within their inventory. But costs nothing and doesn’t hurt to ask should you wish to drop them a line and inquire. But outside of that, Inked Atty is a great source for aftermarket expansion kits if one is looking to gain more juice capacity out of their atomizer
All Day Vape Expansion Kits and Designer Vape Accessories
Edit: Just to add – take note of the device you are using with your Ello Mini. The Mini is only a 22mm tank, it may have been purposely designed to be that size in order to fit certain mods. I own a Vaporesso Swag that also uses a 22mm tank – even if there was a bubble glass option for the tank, it cannot be used given the Swag’s protruding battery cap.