She never did show what she would do with that piece sticking out at the peak of the roof.

I think a tongue depressor would not be sharp enough to do this. I have a "Wooden Iron" which is quite sharp at the tip, but I think this tool would do the best job.

Herta Marker for applique
 

I tried to bring up the video but only got an ad with another link for related books from Martindale. No video on marking applique.

This is my thought exactly.

She tucks it under when she gets to that spot.

Are you at the beginning of the video, or the end?

When I click the link, it goes directly into the tutorial. There is a promotion at the end of the video that shows some of Yoko's books and projects.

I would worry about it being too sharp and damaging the threads in the fabric.

I’m a bit nervous, too about that stilleto/needle thing but I did watch the Yoko Saito video and was blown away. I did a sort of show and tell last year about the Hera marker and how to use it for marking quilting lines without any type of marking tool. When I watched her video it hit me how easily edges would turn over without using templates, etc. I’m a needle turn appliqué and would like,to,show this to my little appliqué group - just running the Hera around a Mylar Template that has curves seems like a great idea.