Currently the XPP system restores the hyphenation language setting at the end of a tag, but not the h&j table.
As the h&j table contains settings about min/max characters in the hyphenated word and these settings vary according to the language you are using, these does not seem right.
Let me give another use case where you want the H&J table to be restored at the end of a tag:
<para>This is a para of text with in it a url which you only want to hyphenate at the forward slashes.
The url comes somewhere in the middle of the text like here: <url>thisisaverylong/.../</url>
and then the text simply continues and you would liketoseehyphenationagain the system to use the normal h&j table again</para>
For the url you want to use a different H&J table because you want the url only to be hyphenated at the '/' character. but once the url is finished you want to use the normal hyphenation table to be used.
Currently that does not happen. The 'special' h&j table you are using for the url will be used for the rest of the para that is following the url