Had no bad batches at home scale, but quite often get these events, when even replacing the lock with an open fermenter does not help. Only regular cleanups work.
This is extra notorious escapee, witbier (OG 1065) made to dump frozen berries that remain in my freezer. And my very vigorous yeast.
That’s quite nice in CZ. The laws are quite a bit more preferential for smaller breweries - same requirements but lower tax. In the end it’s not that hard to make brew pub or smaller brewery.
For sending beer (not taxed and for free), I don’t have good option. It is possible but has to be correctly marked on the package, in the EU I just don’t know.