Adding to this elder thread as this is an ongoing issue for me on my VB-R-099.
I requested the updated C-clip from Chris at Velobuild. Per his statement the R-099 was not affected while I certainly had an issue with headset play.
Re-did the cabling, while doing so changed back to compressionless housing and put in the new C-clip.
Still could not get rid of the headset play, while trying to adjust it I realized another issue with the external stem and handlebar combo.
When you tighten the cap bolt, the cap actually starts deforming and moving side ways - so most of the bolt tension is wasted in the top cap and not in compressing the actual headset.
Cut and glued together some washers, which allowed compressing the system and removing the play from the headset.
Currently freezing and snowing over here, so missing test rides if this finally solved the issue.
My bottom line: the headset design has quite a few tolerances, removing all of them requires careful assembly and potentially changing C-clip or adding washers / shims.
imo the steam design and top cap are not sufficient to remove the headset play, I believe many people resolved it with actually swapping the stem to FSA or deda systems.