I think I can speak on your situation pretty well. I also have a really low tolerance, and I also prefer vaping MTL. Moreover, I primarily use the helix tip on my dynavap, which is what the WoodWynd comes with.
I can definitely vouch for the Tempest. I pretty much only hit it MTL, which makes it really easy to regulate my dosage; I just take as many MTL puffs as I want while the head is hot. Unlike most other convection vapes, you don't need to take a huge, guaranteed-to-melt-your-face (if your low tolerance like us) DTL pull on it to get good vapor.
The flavor on the Tempest is purer, and the high is a much brighter convection high, which personally I prefer over the dynavap's conduction signature. I will say, I still find that the dynavap is better for getting super thick MTL hits, on account of the conduction. Even on the Helix tip, which has more airflow than the other tips and is thus actually worse for MTL pulls. When I french inhale a nicely-roasted dynavap hit, visually the vapor is so dense it's almost looks like smoke, or the vapor from a nicotine vape. The problem is, by that point on the dynavap, the flavor is more or less gone. The Tempest I find has less of a trade-off between flavor and vapor density.
Especially since you already have some dynavaps, I think the Tempest is a no-brainer here. For me, one of the benefits of being a lightweight is that raw performance is not actually that important; I'm more interested in the personality, signature, and ritual of the vape. Either way I'll get high, but I wanna have a fun time getting there, and I want the high itself to be luxurious. The Tempest is really special; it's one of those vapes that becomes not just a tool but a companion.