> We've moved the code out of the CTAN distribution (GitHub "l3trial" 
> directory) as there are some quite important questions that have come
> up that need addressing.

Dear All,

First I'm sorry for two things:
 - my vast ignorance of the LaTeX3 project (though I'm a subscriber of
this list for a few years)
 - I should have sent this mail a few years earlier

In l3luatex, you make use of Heiko's luatex.sty. I don't think it's the
wisest choice: the package luatexbase
(https://github.com/lualatex/luatexbase) is more often updated, and the
reason why there are two packages doing the same thing is because Heiko
is not responding to mails (at least to ours) for more than a year...
The last changes in Heiko's files regarding LuaTeX were even made in
TeXLive by me in order not to break all LuaLaTeX documents.

Maybe Heiko will answer one day and the merge between luatex.sty and
luatexbase.sty will happen, but in the meantime would you give a try to
luatexbase.sty?

If you need any other input, do not hesitate to ask.

Thank you,
-- 
Elie