Thanks for running these detailed "Q" tests between the 1162/46 and 660/46 Liz wire at various frequencies with the HP4342A Q meter. This kind of detailed test is something which would not be my first choice for using up my hobby time, but I'm happy that somebody did it! :-)
The 1162/46 Litz wire's 'Q" advantage on the low band covers the frequencies which are typically checked first during DXpeditions and band scans, so its substitution for the 660/46 Litz wire in 2014 may have given the impression that it was superior throughout the MW range, which apparently isn't so. But to be honest the recent replacement of the old "N50 365P" variable caps with the newer "N50 384P"variable caps seemed to provide a higher "Q" boost in the newer FSL's than the switch in Litz wire, to the extent that it was the inspiration for the miniature "Frequent Flyer' FSL's which have tracked down long range DX in Hawaii and the Cook Islands.
To make matters even more interesting, Oren Elliott seems to have recently improved his manufacturing process in the later "N50 384P" variable caps, so that the N50 384P caps with a "0219" series number are clearly superior to those with a "0217" series number. I don't know if he has been improving the dielectric, rotor or stator, but these newest variable caps are extremely sharp performers-- to the extent that every FSL antenna heading for the Rockwork Cliff this summer will have one of the latest variable cap upgrades. With Hawaii and all overseas travel temporarily scratched out because of the Pandemic, the Rockwork cliff should be a dream DXing venue for both Tom R. and yours truly, who both broke our records for South Pacific NDB-DX last August. Tom told me that he's still uncovering new South Pacific NDB-DX from that trip, in addition to his record-breaking haul already posted.