You've got it exactly right, Gina. People think they can write a one size fits all TPS, but it just doesn't work unless you're always applying for similar work. Some people are like that. They do essentially the same job wherever they go for their whole careers (especially in high school math departments). I may want to borrow some of this reflection if I do the course again -- if that's OK with you.
I was going to suggest somewhere that people imagine a reader, but so many stated that they wanted to do relective pieces for portfolio purposes that I chose not to. I think there might be something to that. In a reflective piece you would want to share a smattering of all different experience that illustrate who you are as a teacher. You could pick 1 big signature idea and show how that is expressed in different contexts. The result would be a useful document to keep as a starting place for any application, but it would also be a snapshot of you right now.
This course has been a labour of love & learning for me. If you want to keep sharing, you can reach me at email@example.com once these forums have closed.