Don
I've seen this set up in picts and articles. They accomplished a Fancy Try to imitate twins... but No Cigar - IMHO! I best like straight drive twin screw (V-drive is my second choice). With twins, when in tight areas either engine can be accelerated in whatever gear necessary to whatever rpm needed to immediately adjust boat's position or speed. Also, to move a twin screw directly sideways with no forward or reverse motion twin screw is the ticket!
Move boat sideways to port (opposite for starboard):
-Turn rudder 80% +/- starboard
-Starboard idle rpm / port approx 150 rpm higher
-Simultaneously place starboard in forward and port in reverse (once in gear adjust rpm as required - higher equivalent rpm % difference, faster the sideways motion - to a point!)
Take it slow: Gently move any boat laterally. Be careful to not get boat moving too quickly as stopping sideways motion takes considerably more rpm, shift, and steerage adjustment time than simply forward or reverse or circular rotation motion adjustments. Adjust rudder and shift/throttle controls as needed for current and wind conditions to move latterly away from dock. Practice makes perfect. I recommend practice in a completely open area... at least at first!