flash and batt bulging - will this be a problem for drywall?

Hi All, I'm finishing my basement and have the following situation. 2x4 framing set back about 1" from the poured concrete walls. I had 1.5" of closed cell foam sprayed and am currently topping that off with R-15 Roxul. Spray foam appears to have been done well, but of course is uneven in places. This causes the Roxul to bulge out up to about 1" but generally 1/4 to 3/4". I understand it is not ideal to compress the insulation, but will the drywallers be able to do it without having screws pop all over the place? Perhaps using 5/8 drywall? Or am I going to have to add furring strips over the studs to provide a little more space? Roxul is not as compressible as fiberglass so I fear my strategy may have just led to more work (i.e., furring strips). Thanks!