If you are comfortable with what you have researched and feel that you have a safe system that is good enough for me.
When you open a thread of conversation about the safety of the system you have set up then you are going to get opinions from others about what you have asked.
Unfortunately those opinions are also going to be all over the map based on what ever experience the folks replying have had.
And the most honest ones will actually have two or three opinions and even those won't always mesh together well.
I will point out a few things from reading the article you found.
First off; good score on finding that one.
I didn't find it or anything like it when I went looking some years back.
For some of us research is not a major skill.
Ok. From what I read the ISGB asked them to conduct a study on the hazards of the light produced while making beads at a Gathering in a hotel ballroom. They also took some samples of the air and took some samples of the hands of six or eight of the bead makers working at the torches.
Here comes another one of those opinions;
This was not a NIOSH study of possible contaminates from working with molten glass on a regular basis.
It was also not a study of the hazards of working with molten glass without "adequate ventilation".
They point out in the conclusion that "adequate ventilation" is required but they make not even an attempt to define it.
The next thing that comes to mind is the table of references lists 11 different studies with the words "glass work" and "cancer" in the titles.
I have not read the references and most likely will not ever get around to reading them.
But the fact that someone conducted the studies and that they were important enough to get cited in a NIOSH report does give me cause to double check that my ventilation system is as good as I think it is.
I did find this statement that gave me some concern;
Page 9 of the pdf (page 4 of the article) Chemical Exposure ;
"Epidemiological studies have indicated that industrial art glass workers have increased mortality risks for certain types of cancer (stomach, colon, lung, skin, and brain) and for cardiovascular and cerebrovascular disease.11,12,13,14,15,16,17 The International Agency for Research on Cancer (IARC) has determined that the manufacture of art glass entails exposures that are probably carcinogenic to humans.18 Glass blowing is one major occupation in the art glass industry which shows an increased cancer risk, possibly because the blow pipe introduces the potential for oral exposure.19"
I think the blow pipe comment is just a little out there as the distance between bower and hot glass on the pipe probably has less to do with it than being in a building with several tons of molten glass cooking away and not having a strict air separation system does but that is again one of those opinions.
No one is ever going to call the ventilation police on anyone and the worst that can really happen is that someone might throw a bunch of exclamation marks at you.
And please understand that I am not saying you are doing it wrong if I happen to disagree with how much is enough.
Only you get to make that decision and anyone who thinks other wise is either fooling themselves or is married to you and we won't go there.
I would love to see someone do a "wipe test and spectrograph" of the inside of the ductwork at the far end of an established lampworkers ventilation system. Preferably someone that torches 6 to 8 hours a day 4 days a week for a half dozen years or more.
Happy torching Jim.
Try not to spend all your money all in one place unless you are buying silver glass or Rubino Oro. Precious metals get more expensive every time you turn around it seems.
Welcome to the addiction.