3B can (and usually does) have no DH and no requirement for a visual reference. A lot of French airports used to have DH15, but no longer. The only one I can find from our regulars is Brescia which is 30/100. No, I don’t know why! All the others have no DH.
On our 767s and older 757s we set -20 Radio. On our newer 757s it doesn’t go below zero, so that’s what we set.
HtH