Any direct in ear where the cable couples to a housing and has no point to dissipate energy from microphonics to your shirt or head first will of course have it. ROCKETS will have some microphonics. We ,however, have added a layer of conductive PVC in the cable to dissipate the small charge generated by a cable when it is flexing. This charge generally causes some microphonics. Having been dissipated by our cable that part is reduced. The cable is pretty soft to be as durable as it is and that helps with microphonics as well. The Y in the cable has a feature to attach it to your clothing nicely which can also help dissipate cable microphonics.
So yes some microphonics to be expected but we did a lot to reduce it as you can see from the above.
It seems you guys have put a lot of work into the cable. I'k curious how you'll implement the remote without undoing the progress you've made. I wonder if it can be integrated into the current Y-split, with the wiring going down an extra layer of sleeving. That way, the remote circuitry and audio circuitry are separate from each other. The idea wood probably need a lot of refinement, but it could be a way of keeping the integrity of the original design.