So I did a deeper dive into plate surface finishes. Or maybe dove off the deep end… you decide! 
Printed the same piece on the Engineering plate that I already had from the textured and Super Tack Pro plates. Same roll of PETG HF, same nozzle size and slicing settings. As before, .6mm nozzle, .62 line width.
So indeed the Engineering plate has a bit more texture to it. However the biggest difference isn’t visual… it’s the freakin’ glue [stick} on the EP. The STP example came off the plate as you see it. The EP sample looked clean enough… 'till I went to wash it off and then you can really feel the glue. Hot water and dish soap gets it off, as does alcohol, but what a pain.
Also, if you print over old glue [stick] that has been printed on already, you’re likely to end up with permanent marks on the bottom surface. The pictures below are of the same piece as the others but I printed it before washing off the plate (I did apply a bit of fresh glue on top of the old). The last thing I printed on it was a filament spool with hexagonal pattern walls (in PC translucent). You can see the pattern… and I can’t get it off the surface of this piece, not with super hot water/soap/scrubbing nor 91% iso. It’s kinda baked-in… subtle but fairly obvious. Perhaps the phenomenon could be used for creative effect!
Cheers,
-Max