It is subtle BS. Leaving out LO, reference tension from any calibrated machine will be the same. That is true for the basic DW to the high end eCP. What may be different could be the final overall tension due to differences in technique and equipment. I mean you could have drawback from the basic DW that does not exist to a significant measure on the eCP. However, if for example RT is used to measure final overall tension for same string in same frame and they both say the same tension, then the frames have the same overall tension in spite of the machinery. To say that one will lose tension faster than the other is not valid except under certain conditions involving static tension loss. If you pull and clamp quickly with the DW vs a slow pulled eCP, you could end up with different tensions. Or you do a fast eCP pull and clamp vs a long pull on the DW. However, I suspect that the end results will not be the same using RT since there is different static tension loss due to creep. Doing it this way means the stringers have different technique and is not a valid comparison. 2 cents.
What the pro is saying is that (perhaps) his machine/technique removes more of the static tension loss than the amateur using his (same) machine. My answer would be 'so, I get the same reference tension with less static tension loss? How can that be if they both end up with the same reference tension?' I would laugh at this assertion.