It’s getting a little late in the day for a contemporary coming-out comedy. Isn’t that battle pretty much over, and aren’t plays like Gemini and Torch Song Trilogy period pieces by now? That said, David Adam Gill gets a fair amount of comic mileage out of Experimenting with Katz, his “new comedic play” about, shades of Albert Innaurato or Harvey Fierstein, Michael Katz (Paul Pakler), a youngish gay man with self-esteem issues, romantic issues, and severe mother issues. Gill hasn’t quite merged his characters and themes into a cohesive whole, and he needs to acquaint himself with the Delete key—Katz, small as it is, runs more than 2½ hours. But he knows how to make us laugh, and, a few contrivances notwithstanding, care a little, too.