I’ve given it another chance and successfully installed pandoc! Thanks for help! I’m still new to macOS (M1 is my first Mac ever), so there are still many things that I don’t quite understand. Converting HTML files one by one through terminal works great, but with few hundreds of notes it will take some time, so I tried to apply your Markdown export script You wrote in this thread (I’ve only changed pandoc directory), but with almost no results i.e. after running script, I get empty markdown files.
I think I will just wait for the TBX 9 
Thanks again!