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Bush vines… do you use pales or sticks or It is a free trellis system?
Anyway advice no. 1 could be good for you.
If you can use sticks and keep the shoots tied maybe it could help, but be sure to protect enough the grapes from the sun.
In some windy areas they use to orientate the trellis parallel with prevailing winds and build up windbreakers ( trees, fences or even walls! )