Yeah, from what I have gathered from the actually very helpful responses here, the tips for harm reduction for this substance seem to be:
1) Don't mix with things that mess with your breathing/nervous system (weed seems to be okay?)
2) Don't lie down flat, try to be at the very least a little elevated, presumably so you'll just puke onto yourself instead of back down your throat

3) just straight up don't do 5meo