Wings are allowed on F16. As long as the overall width does not surpass the 8ft 2inch wide beam.

Straight from the F16 rules.
1.2.2 The maximum overall beam measured on the platform is 2.50 mtr. (= 8,2 ft.)

1.2.3 Wings may be carried as long as the equivalent overall beam when measured over the platform and one fully extended wing is 2,50 mtr. or less.

If you are racing in a open class you can use wings to whatever dimensions. I really dunno how it would affect your DPN.

Wings are not offered yet because the F16 is still a realtively new class. Plus from a performance stand point I dont think they are an advantage, reason is because the leeward wing can dig into the water.