Talk to GC and have them send you some pics of their SEM images of the material when its etched, Im sure they have that.
I always etch every crown, even if its not being bonded. IMO its impossible to etch emax for under 10 seconds without getting the white haze. if thats a problem, then every crown Ive ever done has been over etched. Im not sure what else you do other than dilute it more or leave it on for a few seconds..
LiSi is nice but im not sure its comparative to emax, color-wise its better, strength-wise Im not sure, Ive had some issues.. Im not even really seeing hardly any all ceramic crowns anymore, everything is done in zr except for veneers.. that is a trend I just noticed this year...