My instapot brand I can pretty much control the temperature directly, so it shouldn't be a problem, and yeah, I was told the same 118°-220°F is supposed to be ideal to break the chemical bonds without destroying them. I saw this really cool idea, a "beer can chicken rack." a circular doohickey that sits in the bottom and can hold the jar up, then pour water up to half way up the jar; fill it with product, seal the jar and presto chango! (ok, so there is more to it, here:
Ah yes, the smell, or lack thereof, of success)
I totally wanna try it, but use the temperatures recommended that we're talking about, and not for butter, but for carboxylation. The good thing, if the jar ever explodes (it's not under pressure the entire time, and not under high pressure), it never goes anywhere, any the smell will be absorbed into the water (a friend tells me.) I was also told, if you are worried about the smell at all; when you vent the pot, vent it into a bathtowel (like when I blow my vape in Big Brother's house LOLOL.)