i guess, it depends on how narrow or broad our definition of "inserting" is.

yours is pretty broad, if you see that term "insert" already by reading as putting yourself into the story.

I see it more narrow, as in really writing a character modelled after yourself, to interact with the other fictional characters in the story.

so, i mary sued myself a lot on my teenage years into my imaginery stories in my brain. it helped a lot to escape from the banality of real life.