Sure is. My very first run-in with dudding came from a "trusted vendor" (and I had peeps here waiting on cuts from that plant) To say I'm relieved life got in the way of me sending is an understatement! Testing is a great tool, but more importantly, I observe the plants closely thru several cycles to really be sure.
One thing about observation is that sometimes it can be grower or environment related as opposed to HPLvD. I have had teens bunched in a tent once with a low level T-5 light and some of the lower branches were going more out then up, trying to find light, with three finger leaves (some of which overlapped) and the stems were weak (didn't have any air movement in there)
Sent a few sample in for testing to make sure none of the teens were dudded and all came back negative. They are now in another persons indoor garden blowing up and stacking.
The test does not 100% clear the plant from any HPLvD. Multiple tests are definitely needed. I mean I am testing some decent sized mothers most of the time so just 3 leaves may not pick out the virus.
I will be honest. I do not deal with many strainly vendors at all anymore even being one myself. I do not see many mentioning testing cuts in their methods and the way this thing transfers is like a game of hot potato for most. I mean this is a virus that people should be weeding out. It is mechanically transferred which means by human error. It is not some bug, it does not live in the soil or the water. It is in a plant and transferred to another through mainly human hands although there are some instances where bunching and rubbing may transfer. Knowing the source of the clones may help but that only can go so far. If Darkheart is point A then even with their history I trust point A. If someone without testing in their garden is point b then I am skeptical as hell. I will say this. I did grab cuts from MadScientist (MAC, Sundae Driver (Black sheep farm cut), Cherry pie, and Ice cream cake) not one of those tested out positive and the Apple Fritter from Mainely who has been probably tested the most next to the Ice Cream cake, has come back negative every time. But then you go and look at Mainely's page and all of a sudden you see at some point he even got the virus. The Fritter sticks around because its verified but from now on we only take in cuts from distributors that are leading the forefront in testing. Node labs, Darkheart nursery, Purple city genetics..... And even those we will test out still just to ensure that any coming in may not have been missed but those three companies run vigorous testing. Makes our testing look petty. But the goal is to isolate it out and garbage anything with it. If everyone had access to well priced solid genetics I feel like they would be more than willing to get testing done and part with the crap that has it. Then start fresh with less opportunity of bringing it in.
One side note. Its rate in seed form has also increased. I believe it is still below 10% but that is enough to say that seeds can be a carrier as well. So people popping seeds of genetics that may be known for it may want to run some testing as well.
Everyone should be reading DarkHearts white paper and their 3 part series about HPLvD. Great informative stuff in there. One thing I found reassuring is that the virus itself needs a living host to actually live. Its RNA sequencing basically only lasts about 2 hours in inanimate vectors. This means it is most likely not in your water supply, It is not in previous seasons soil, the transfer from pests is a low rate, it is not some sort of having to scrub down an entire room with bleach type issue.
Clone distributors need to be more part of the solution than the problem. We all love this plant and want to see it thrive to the best of its ability.