Ltree: set of allowed charcters is limited to [A-Za-z0-9_]. Could the dash "-" be included?

Dear friends,

I would like to use ltree for search paths in a warehouse application,
something like "Material-Entry-01.Main-Aisle.Shelf-Aisle-R07/R08.R07-12-03"
Unfortunately I can not use common separators like dash (-) or slash(/)

Documentation states only thes characters [A-Za-z0-9_] are allowed.
https://www.postgresql.org/docs/10/static/ltree.html

As far as I can see this limitation is set in source code of ltree, line 83:
https://doxygen.postgresql.org/ltree_8h_source.html
#define ISALNUM(x) ( t_isalpha(x) || t_isdigit(x) || ( pg_mblen(x) == 1 &&
t_iseq((x), '_') ) )

I would appreciate if at least the dash (-) and perhaps also the slash(/)
would be included to the list of allowed characters.

It is not only me, also other users are interested in this feature, some of
them even changed the source code themselves to recompile their own
Postgresql version..
https://stackoverflow.com/questions/29887093/valid-characters-in-postgres-ltree-label-in-utf8-charset/34057357

best regards

Jörn Jaenecke