REL Strata iii connected to Krell KAV-250A

Hi, 

I want to connect a REL Strata iii to a Krell KAV-250A. I need confirmation back on the proper way to do this. I have reached out to REL (no response). However I also do not have confirmation on all the facts either. 

For example :

1.) Relative to the support posting below -  is a Krell KAV-250A a differential amp? Should it be connected as described in the support link below? Note that I am not using the XLR inputs, and I have the jumper connecting pins 1 & 3 so the amp is inverted. 

2.) I have read that when not using the balanced XLR inputs the XLR inputs should be jumped between pins 1 & 3, which makes the amp outputs invert the signal. However, also looking at the specs it appears that jumpering pins 1 & 2 the output is not inverted. I understand the issue of inversion as relates to direct, or inverting preamps. Is there some reason why inverting is the preferred reccomended mode? The docs make no reference to the type of input being used. What I am looking for is a best practice relative to the design of this amp when I am using an inverting, or a non inverting amp. The last part of the equation is potentially to just reverse the polarity relative to the speakers my switching the connection at the amp outputs, or speaker inputs. 

relsupport.zendesk.com/hc/en-us/articles/115004648928-Differential-Amp-Connection-Method

Thanks!