Since the VTR will be coming with an included adapter, you will be able to use 510 and ego threaded juice delivery systems with the VTR, if I understood the info correctly. It is just that your topper may have to sit on top of the device, like the MVP or MVP2. Kind of a shame, but it is what it is. Even if the Evod fits in the space and can connect, will it be tall enough to be able to use the unchangeable drip tip on the Evod? Without having the box device half shoved in your mouth? Sorry for that mental picture.