I have gotten Wheezeworts to reduce the temperatures of hydrogen to below -200 degrees without becoming Stifled. My stream viewers believed it was a problem with other gasses at higher temperatures in the wheezeworts, However, some of the wheezeworts only contained -200 C hydrogen gas and were not stifled. I believe it has to do with the vacuum at the base of the wheezeworts that forms when wheezeworts are next to one another.
I'm not very good at bug reports, but I have video you might be bale to gleam more out of https://www.twitch.tv/videos/133895290 Starting at about the 1:52:00 mark. Sorry I can't be of more help.
Steps to Reproduce
1) Make a room with a Gas pump on one end, a Gas vent on the other, Natural tiles between and connect the pump to the vent, so Hydrogen can be recycled. 2) Plant numerous wheezeworts on the natural tiles right next to each other. 3) Pump in Hydrogen gas. 4) Run the system.
This issue has not been confirmed by a developer yet.