My two cents. I've made thousands of vcarved cedar signs (used to take my smaller CNC to the Christmas fair every year and make signs to order - fun and hectic). Sharp bit, 60-70ipm, 15k, mostly Artcam toolpaths which basically carves each side of the groove separately, don't know about Vectric, about every font that you can imagine. 2002 PRT w/upgrade box. Very few issues like pictured. I was carving into blanks prefinished with Helmsman Spar Varnish, so it may be a coat of Shellac or other sealer may help you. And, as mentioned in an earlier post, I tried to buy clear, vertical grain cedar, though always ended up with something of a mix of grain patterns. Don't know if any of this helps, just wanted to post a system that works for me.

On a side note, I had a lot of issues with bleeding, the worst was kinda borderline to me, but nobody ever complained. Best results were consistently with close growth, vertical grain, worst with flat grain. When in the shop, using a mask and spraying the vcarve with shellac before painting helped a lot on prefinished blanks. Raw wood, shellac before and after vcarve helped.