I'm sure that backing mesh has its advantages, but if I was learning to fix mosaic, I'd want to do it without an aid.
My guess is you're not always gonna be in a position to use it, I'm sure it'll be cost prohibitive at times.
And if u've only ever used the mesh, surely it's gonna be a much more difficult task without.
I've never used it so I can't really comment I suppose, but last time I looked it was around a £1 a sheet, that's gonna add £11 a metre!
I've used it a few times, it was only for packing out borders so not many sheets were needed which makes it low cost. You wouldn't want to use them for doing full walls as it eliminates the option to slice through the mesh and adjust sheets to line up better