Mid June 2023. Here some commented pictures of the living hedge.
The living hedge is being filled by branches and leaves. I still notice some holes in it, it is definitely not going to be animal proof.
Overall it's working well, but there are some points of attention:
Another overall view of the hedge from another side
Detail on the base of a pletcher that did not resprout much
This elm pletcher resprouted a lot from the base and lots of shoots fill the space a low level
In terms of plant species (elm, maple, evonimous, black locust) I can say that all seem to have reacted in the expected way and gave some sprouting from the base and the side of the inclined branches (pletchers). There's a lot of variability from one plant to another, though. What seem to be most important in resprouting is access to light.
I looks like the hedge will require some work next year both to trim it and to redirect some of the basal sprouts..."to weave them in" for achieving a better filling of the space.
My current feeling is that it is very difficult to make the hedge wild-bore proof (although good enough for cattle and people), but it can be part of a multilayered system. Coupling it with barbed wire, a dead branches hedge or some metal fence has the potential of doing the job with some minimal materials investment.
Conclusion: yes, it works!