Well that's because the phrase is "blowing smoke up my ass" not "blowing hot air up my ass". You're probably mixing it up with someone being "full of hot air".
It comes from an actual medical procedure way back in the day where doctors would, well, blow smoke up your ass.
I'm also a heavy Obsidian user, but yes it's a full featured markdown editor.
Heynote does exactly what you like from notepad++ (persistent buffer, no saving) but instead of tabs you can press ctrl+enter and just start a new note (with line numbers starting over at 1) right below the previous one.
On top of that, hit ctrl+L and you can pick your language and get some nice formatting.
And the other countries that have sanctions but still got tariffs?