I personally have never loved milling wax veneers, but the ceramists I've worked with say they save time so I still do them. That said, besides general fit, are you having to reseal margins? That has been my biggest concern with printing (outside of having to finish fencing off the occlusion etc.) If you do have to seal the margins, or make any other modification for that matter, can you work with the 3d printed material, or do you just have to go a different route?
One last note, have you printed other restorations than veneers? It would seem that veneers of any restoration you would print, would be the easiest in terms of support, I could be thinking about it wrong though