> Setting priority did not change this behavior (but, afaik, 
> that only applies for equal import precedence).

yes and in any case never has any effect when calling templates by name,
it only affects the template matching rules.

I think the template with highest import precedence should be used.

If you add

    <xsl:template name="x">
      <xsl:call-template name="main"/>
    </xsl:template>


to importing.xsl and  start saxon with -it x then it does output <high-precedence/>
as you'd expect.

I think it's probably a bug.

David