I would love this style bra for a 32ddd! It is impossible to find a bralette let alone merino that fits well. Please make it happen!
I would absolutely buy a couple of wool bras in this style BUT they gave to have pockets to accommodate F or G size removable cups and they have to be offered with a sufficiently small band size.
As others are saying, a wool bra sounds awesome, but S/M/L sizing will not work for me. My measurements are 28" underbust and 40" bust, which usually works out to an XS in the band and a L in the bust. I can't wear either size, nor does it work to compromise on a size in the middle: the result is either a too-loose band with no support and boobs falling out the bottom, or not enough room in the cup and everything spilling out on the top. There are already other brands making S/M/L sized wool bras for those who can wear them. Do something different.
If you need ideas on sizing scales, check out Molke. They have three different sizing systems for their different bra designs. All easier than the traditional band and cup size, but much more inclusive of a variety of sizes.
I adore merino bras -- a persistent problem is that they are scaled for B cup and very difficult for those of use with larger cup sizes. There are currently non on the market that have the little pocket for an insert (for those concerned about nipples showing). How wonderful it would be to have a merino bra with a merino insert that worked on a DDD. Since this is right next to the body, 100% merino would be ideal (and ecologically better).
I would love a wool bra that is thick enough to not show my nipples through it, but also can be maneuvered so that I can breastfeed with it on!