Extreme (> 20 percent) 1.4.0 benefits found in the wild - by coincidence, and without going to 88.2 kHz or higher.
Yes 48/24 files, but also a few 44.1/24 that save some ten percent.
https://lustmord.bandcamp.com/album/alter is available at "name your price".
(If you want to buy at Bandcamp, wait until "Bandcamp Friday" where they waive their cut. I've started buying from Boomkat instead after Bandcamp canceled my purchase post payment just because.)
A bit trying back and forth suggests they used -6, that gives straight 1.000 ratios.
Now look at 1.4.0 at -3:
C:\tmp\Lustmord & Karin Park - ALTER> C:\bin\flac-1.4.0-win\Win64\flac.exe -3f *.flac
flac 1.4.0
Copyright (C) 2000-2009 Josh Coalson, 2011-2022 Xiph.Org Foundation
flac comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
welcome to redistribute it under certain conditions. Type `flac' for details.
Lustmord & Karin Park - ALTER - 01 Hiraeth.flac: wrote 52035408 bytes, ratio=0,981
Lustmord & Karin Park - ALTER - 02 The Void Between.flac: wrote 59625894 bytes, ratio=0,899
Lustmord & Karin Park - ALTER - 03 Perihelion.flac: wrote 32100437 bytes, ratio=0,845
Lustmord & Karin Park - ALTER - 04 Twin Flames.flac: wrote 83337766 bytes, ratio=0,914
Lustmord & Karin Park - ALTER - 05 Entwined.flac: wrote 75526535 bytes, ratio=0,956
Lustmord & Karin Park - ALTER - 06 Kindred.flac: wrote 53892745 bytes, ratio=0,839
Lustmord & Karin Park - ALTER - 07 Song of Sol.flac: wrote 55486784 bytes, ratio=0,898
Lustmord & Karin Park - ALTER - 08 Sele.flac: wrote 64500002 bytes, ratio=0,879
... saves nearly ten percent on the total.
Deleting, re-extracting from .zip, and running -8p (no "e" ...)
PS C:\tmp\Lustmord & Karin Park - ALTER> C:\bin\flac-1.4.0-win\Win64\flac.exe -8pf *.flac
flac 1.4.0
Copyright (C) 2000-2009 Josh Coalson, 2011-2022 Xiph.Org Foundation
flac comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
welcome to redistribute it under certain conditions. Type `flac' for details.
Lustmord & Karin Park - ALTER - 01 Hiraeth.flac: wrote 47871959 bytes, ratio=0,903
Lustmord & Karin Park - ALTER - 02 The Void Between.flac: wrote 53662309 bytes, ratio=0,809
Lustmord & Karin Park - ALTER - 03 Perihelion.flac: wrote 28090623 bytes, ratio=0,739
Lustmord & Karin Park - ALTER - 04 Twin Flames.flac: wrote 71762047 bytes, ratio=0,787
Lustmord & Karin Park - ALTER - 05 Entwined.flac: wrote 65022030 bytes, ratio=0,823
Lustmord & Karin Park - ALTER - 06 Kindred.flac: wrote 48006888 bytes, ratio=0,748
Lustmord & Karin Park - ALTER - 07 Song of Sol.flac: wrote 48319869 bytes, ratio=0,782
Lustmord & Karin Park - ALTER - 08 Sele.flac: wrote 55920678 bytes, ratio=0,763
... and no, the 1.3.4 at -8pf doesn't do wonders, it is the 1.4.0. Download and test for yourself.
-e not tested. Probably makes a difference for 1.3.4.
I came up with this by the following coincidence: Spotify on my soon-falling-apart desktop computer suggested a new Lustmord tribute/remix CD with some damn interesting names, and then a crash. Went to laptop, googled, found it at "name your price" together with the one above: https://lustmord.bandcamp.com/album/the-others-lustmord-deconstructed
OK, so this was the one I actually googled for - and it is 44.1/24. Again, testing with -6 gives straight 1.000 ratios, and let's hit it with 1.4.0 at -8pf (again, no "e" here):
Lustmord - The Others -Lustmord Deconstructed- - 01 Enslaved - Eon.flac: wrote 42854726 bytes, ratio=0,922
Lustmord - The Others -Lustmord Deconstructed- - 02 MONO - Er Eb Os.flac: wrote 76787106 bytes, ratio=0,873
Lustmord - The Others -Lustmord Deconstructed- - 03 Ihsahn - Dark Awakening.flac: wrote 39634289 bytes, ratio=0,923
Lustmord - The Others -Lustmord Deconstructed- - 04 Jo Quail - Prime.flac: wrote 74264091 bytes, ratio=0,900
Lustmord - The Others -Lustmord Deconstructed- - 05 Bohren & der Club of Gore - Plateau.flac: wrote 118575065 bytes, ratio=0,986
Lustmord - The Others -Lustmord Deconstructed- - 06 hackedepicciotto - Trinity Past.flac: wrote 65398218 bytes, ratio=0,905
Lustmord - The Others -Lustmord Deconstructed- - 07 Ulver - Godeater.flac: wrote 113619735 bytes, ratio=0,981
Lustmord - The Others -Lustmord Deconstructed- - 08 Jonas Renkse - Er Eb Os.flac: wrote 70867405 bytes, ratio=0,971
Lustmord - The Others -Lustmord Deconstructed- - 09 Zola Jesus - Prime.flac: wrote 37000037 bytes, ratio=0,889
Lustmord - The Others -Lustmord Deconstructed- - 10 Spotlights - Of Eons.flac: wrote 76565255 bytes, ratio=0,935
Lustmord - The Others -Lustmord Deconstructed- - 11 The Ocean - Primal -State of Being-.flac: wrote 116101117 bytes, ratio=0,994
Lustmord - The Others -Lustmord Deconstructed- - 12 CROWN - Element.flac: wrote 58738240 bytes, ratio=0,999
Lustmord - The Others -Lustmord Deconstructed- - 13 Jaye Jayle - Er Eb Es.flac: wrote 44316148 bytes, ratio=0,928
Lustmord - The Others -Lustmord Deconstructed- - 14 Godflesh - Ashen.flac: wrote 70261802 bytes, ratio=0,979
Lustmord - The Others -Lustmord Deconstructed- - 15 Steve von Till a.k.a. Harvestman - Testament.flac: wrote 79120831 bytes, ratio=0,994
Lustmord - The Others -Lustmord Deconstructed- - 16 Årabrot - The Last Days -See the Light-.flac: wrote 86782738 bytes, ratio=0,997
Still three tracks do hit the ten percent mark. Again, it is the 1.4.0 that makes the difference; recompressing the download by 1.3.4 at -8pf gives at best .992.