SLOP is required by US carriers (maybe all of ICAO). But I often use a SLOP of "0" if there is a left crosswind. Fortunately the authorities were smart enough to include that as an option. Wake encounters happen even when the guidelines are followed. I caught it climbing through 200' out of Atlanta just a couple of days ago. The recovery briefly required full left aileron. The previous airplane was a lowly MD80 (mine was an even lowlyer 737-700).