Yes, ACE was the "default" supplier of barrels for Vudoo, and I guess remains so. But as the top-tier rimfire market has grown - exploded - since Vudoo kicked open the door in 2017, customers have become more knowledgeable and want barrels from known top-shelf suppliers. My understanding is that ACE quality has deteriorated since the pandemic- most barrels shoot, some just won't.
I have a buddy who asked me whether to order an ACE or Bartlein barrel for his first Vudoo last summer. I opined that he should get a Bartlein if he was willing to wait (supply was tight for ALL the Bartlein contours), or go with the Ace if he wanted faster delivery. He went with Ace. Long story short, that bleeping thing wouldn't shoot for beans, and Vudoo made it right and Bartlein is now in the house.
As I posted earlier, I had Vudoo rebarrel my gen-1 Vudoo with a Bartlein (MTU profile cut to 22") to replace the original almost-20-inch ACE/Kukri. I chose that profile because I didn't have to wait months for the kool-kids-straight contour and I chose 22" instead of longer because it's been reported by Vudoo and other precision rimfire experts that 22" is as optimal for a "PRS-intended" repeater as it gets (and I had a 26" Shilen barrel on my RimX which bled off so much velocity that I had four inches cut off it; the experience left me, rightly or wrongly, hesitant to "go long").