I just bought an EoTech 511 and a PRI standard gooseneck mount for my Bushmaster A2 shorty, 14.5" H-Bar.   I  installed the mount and I find that it doesn't set down on the handgaurd like I thought it would, is this normal?   There's about a 3/16" gap between the mount and hand guard
   
      The instuctions say that the mount can be set up for absolute co-witness or lower 25 % co-witness but they don't go into detail how to do either.  What am I missing?   Are  the instructions discribing 2 different cheek welds or can the mount be physically setup for 2 different co-witness?  

   The way it's mounted now When I look thru the Irons I can barely see the top of the front sight post in the EoTech,is this normal?  

  Also the mount has a square of foam padding on the bottom at the front of it.   Is this foam supposed to stay on ?   If it is how heat resistant is it?

  Thanks fr any and all help!