Thanks for pointing that thread out, although it seems to support my thinking that there is no sure answer towards definitive safety or lack thereof when utilizing 5-MeO-DMT.
Between the cautionary literature found in Appendix Six of
Tryptamine Palace, and "Negative Reactions and Precautionary Practices" from the
Toad and the Jaguar, it seems that a host of unpleasant phenomenon remains quite possible (in
Toad And Jaguar Metzner speculates this can be expected in about 10% of users), but nothing points towards respiratory arrest directly. Varying degrees of depersonalization following the experience seems to be the more likely undesirable reaction - and although not pleasant, would not be a direct threat to the meat body waiting back in my room.
Part of my concern lay in the fact that I almost militantly prefer to use tryptamines in a solo setting (I'm able to get more productive results in solitude,) but don't want to jeopardize my own health in my pursuits.
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents." -lovecraft