I admit I haven't tried scape pesto yet. Shortage of nuts!
But I have done pizza with a garlic/oil/rosemary/parmesan and chopped nuts instead of tomato.
That was some years ago though, in the days before soooo many tomatoes.
The scapes are very mild to me... in a stir fry, they make a great substitute for green beans (which are waaay harder to grow here). But in general we do lean toward strong garlic flavors in our food, lots of it.
So I imagine scape pesto would be mild by comparison to what we usually go for.
I can't believe I'm at the point of looking for substitutes for tomatoes.
(Yes I still have a few bags of em in the freezer)