Practice Chanter Pakistani ABW GHB's, double toning, no tune

Black wood Pakistani pipes, double toning on the bass. These pipes will tune all the way up to 486hz and beyond, but they came with a 466hz chanter??? I've set them up with Balance Tone drone reeds on top of extenders, but the lower pitch is right at the maximum of the bottom end of the drones. The chanter has a Caldwell ridge cut easy reed. The blow pipe has a crack in it that is only visible and leaks after about 20 minutes of playing, which for a fairly weak player such as myself was frustrating at first because my “tone“ would suddenly go away for no apparent reason. Hence, no tune from these pipes until the replacement blowpipe arrives. But, I thought it would be useful for new pipers to hear what actual double toning is. I think it happens because the tuning chamber is too large for the design of the reed and the pressure is just slightly below the full harmonic of the blade.