If applied with rend aid then the mesh is applied onto, applied in first pass then it's re enforcing the render and adding strength.
Surely adding it to the substrate is basically using it like scrim tape
You mean stick the mesh in with the rendaid? Never tried it but then the mesh isn't part of the render, you'd essentially have one thick sheet of render sat ontopnof mesh rather than the mesh re enforcing the render.
I've also never tried spraying rend aid. Suppose you could but I wouldn't fancy it
One 17mm pass on rendaid will sag like f**k with most materials.
I like to bed mesh in 5ishmm then top with 10ish.
The first pass will take a second quite quickly on rendaid in the summer buy obviously not so much as it gets colder