Echoing a lot of other people, I would just use your dyna to vape CBD. It will still perform admirably, so I'm not sure why you think you need a backup for it.
If you just want a backup to try something different that is a thing, but I would personally swing for something like an Xmax v3 pro to experience what full convection is like (dyna's are heavily biased towards conduction). There is some validity to trying a few different styles out to see what you like, but given what you are spending now (assuming Dynavap M + IH + some kind of backup vape) I personally might be inclined to just get one really nice vape at this point, but its your call.
I do generally agree with the sentiment that its wise to start with just a torch with your Dyna. In your case if you find it to be a PITA to use due to arthritis an IH might make a lot of sense. Otherwise IMO they are more of a nice to have than a necessity. A lot of people swear by them, but to me they didn't improve the vapor or make my vapcaps do anything I couldn't already do with a torch. They are just a little more convenient/easier to use (especially outdoors, but again if I'm bringing a dynavap along I personally don't want the weight or risk of damaging an IH). I think as
@bossman alluded to a lot of the "YoU mUsT gEt An Ih WiTh YoUr DyNa" you see here and on reddit is just people who bought one with their dyna and have never used it otherwise. Thats cool, just be aware you're paying a rather large premium for that convenience if that is all it is to you.
