We usually smoke everything we have a couple of kms before the border, just to be sure we have nothing when they are going to check on us, after all that's their job, they're gonna check anyway.
It also happened on the border to Slovenia, with my girlfriend, they separated us and told me they had a new test that detected every known drug and could charge me on the account of using.
I laughed so hard that they let us go.
So you coming rolling up smelling heavily of weed, and for some reason they insist on searching you for weed? How weird. I feel like there's a way to avoid that.
Be sure to not bring anything that may cause troubles, but don't worry if they treat you like a troublemaker, it's just their job.
You're on a van, packed with stuff, you dress weird, you look weird, you probably haven't slept properly the night before, they are going to search you, no matter what.
Even more so if you have merch with you, for example in Switzerland they want you to pay taxes on the merch you sell, so they try as hard as they can to get an idea of how much money you're going to make so that they can charge you on the way back, when you leave the country.
That's what crossing borders with bands (mostly american) taught me.
There is no passport check if you are an EU citizen, but the border still exists.