I've set the 4.2d up two ways.
-DT kit. Works well.
-2 layers strapping tape and 1 layer of electrical tape. Use a valve stem cut out of a tube.
The DT kit's valves have removable cores, which is nice if you need to get a faster burst of air or inject sealant without breaking the bead. But that's really the only advantage. Using strapping tape and electrical tape worked really well on these rims.