Good to hear you’ve had some success.
Strange that your Omnifocus is having problem with the script output…as far as I know the script is outputting standard text encoding with no special characters. I’m unable to test import, as I don’t use OmniFocus, ( I use pure Taskpaper with the offical app ).
Tasks with Notes - Yes, that should be certainly possible. You could have a go at amending my script, if you like.
I might be persauded to have a go myself…but I won’t have time to have a look until the weekend.
All the best.