I was just browsing the S&W forums where someone mentioned that NDZ Performance just released something similar to the Magpul BAD Lever. This thing is designed specifically for the M&P15-22 and won't have problems fitting on like the BAD lever. I just ordered one and will review it when I get a chance.
http://www.ndzperformance.com/NDZ-Performance-S-W-M-P-15-22-SBR-p/ndz-sw-sbr.htm
http://www.ndzperformance.com/NDZ-Performance-S-W-M-P-15-22-SBR-p/ndz-sw-sbr.htm