I went to GotVapes to get some Mini Vivi Nova metal tubes and saw they have regular size Vivi Nova's with metal tubes with a clear window. Sadly, no minis. I expect the clear part will be plastic but I ordered one hoping it will be possible to replace it with some glass stuck on with food grade silicone adhesive.
Link to photo of GotVapes VISION STV ViVi NOVA 3.5ml REBUILDABLE TANKS with the windows.
I didn't even know there was such a thing as a Kanger T4 are but I ordered some to see if they are as fabulous as the T3s but might be easier to fill and dry more quickly.
5 - Kanger T4 510 Slim Clear Cartomizers 1ml 2.2ohm
2 - Additional Mouth Pieces for Kanger T4
2 - Mini ViVi Nova Metal Tubes