Valid characters in a module name

[Ess Kay]

"JPMS: Modules in the Java Language and JVM" at
http://cr.openjdk.java.net/~mr/jigsaw/spec/lang-vm.html#jigsaw-2.6 says
that a module name can contain almost any character.  If this is indeed the
case then it is going to make the development of scripting languages that
specify module names quite complicated.

Would it be too big a compromise to specify that a module name must not
contain
1) double quotes,
2) single quotes,
3) spaces,
4) forward slashes or
5) asterixes?
Put another way, what advantage is there in allowing a module name to start
with or contain a double quote or space etc?

Taking a step backwards, would it be too much of a compromise to specify
that module names should only contain characters that are valid in a Java
class name perhaps with the exception of a few special characters?