well obviously inhalation safety is most important.
If that was true in every case then 7th floor would never sell any tubing, afaikt most SSV owners use 7th's tubing not ptfe/silicon ....so it seems flexibility trumps safety for most people.
Unlike ptfe/silicon there is no public data sheet available for 7ths tubing which means the operating tolerances, max temp etc are unknown.
But, we do know that Vinyl begins to give off toxic gases at much lower temperatures compared to ptfe/silicon.
Ime, Vinyl gives off gases at room temperature....anyone with a vinyl record collection will confirm that
it smells when removed from the sleeve, while 7th's tubing doesn't smell quite as strong...it still smells which means its essentially off-gassing
something.
My ptfe tubing on the other hand doesn't smell/taste of anything, which is why it's used in labs by scientists/chemists & only in situations where it's impossible to use glass.....try getting those guys to use Vinyl, never going to happen, safety first!