Many thanks for this new batch of UXP-based forks!
I, for one, am not taking these builds of yours for granted, they do require dedication and considerable effort on your part (despite "upstream" constantly belittling your offerings as being just "hackjobs" ... ).
Be that as it may, might I also kindly ask why the official UXP issue #1694,
https://repo.palemoon.org/MoonchildProductions/UXP/issues/1694
and official Bk issue #31,
https://repo.palemoon.org/moonchildproductions/basilisk/issues/31
were backed-out from your custom UXP branch?
The thing is I was actually following closely the original report in the official forums,
https://forum.palemoon.org/viewtopic.php?f=61&t=25728
and immediately thought that would be a favourable change to implement; after all, MCP would just be restoring what was already extant in Mozilla v51.0 and later broken by Mozilla devs in v52.0 of their platform...
E.g. my (custom) date/time format configuration in my system is "dd/MM/yyyy HH:mm"; New Moon 28 respects that setting,
because, while the platform code is a Mozilla v52.6 fork, the application code itself is a Firefox < 52.0 fork, so not affected...
OTOH, latest Serpent 52.9.0 does not respect my custom date/time format OS configuration,
because both app+platform code are Mozilla v52.6 forks and inherit the Mozilla caused breakage,,,
As a result, Serpent displays date/time in a non-user-configurable US+12h clock format "M/d/yyyy, h:mm tt" ; me personally, I would have liked uniformity between NM28 and St52; what do other members here think?
For the record, Mozilla, in later versions of their Firefox browser, tied date/time display to browser locale being used, but even then, the display format is fixed/non-configurable... With Serpent 52.9.0 (and now, sadly, NM28 too...) being only an en-US localised app, this is a moot point...
This is just a thought, but perhaps issues UXP#1694 + Bk#31 could be implemented in our tree behind a user (i.e. about:config) pref? ...
Kindest, warmest greetings!