XSLT Optimizing xsl:choose and str:tokenize - xslt

Question

I have been researching and haven't been able to find anything related to optimizing XSLT. Below is the snippet that I am working on and wanted to see if anything can be done to help with the xslt transformation.
<xsl:template match="a:OBR/*">
<xsl:choose>
<xsl:when test ="name() = 'OBR-10' and string-length(.) = 0">
<OBR-10>USER</OBR-10>
</xsl:when>
<xsl:when test ="name() = 'OBR-18'">
<OBR-18>
<xsl:value-of select ="//a:PV1/a:PV1-44"/>
</OBR-18>
</xsl:when>
<xsl:when test ="name() = 'OBR-19'">
<OBR-19>
<xsl:if test = "string-length(str:tokenize(../a:OBR-18,'^')[5]) > 0">
<xsl:value-of select ="str:tokenize(../a:OBR-18,'^')[5]"/>
</xsl:if>
</OBR-19>
</xsl:when>
<xsl:when test ="name() = 'OBR-33'">
<OBR-33>
<xsl:value-of select ="translate(../parent::a:ORC[1]/a:ORC-4,'^','~')"/>
</OBR-33>
</xsl:when>
<xsl:when test="name()='NTE'">
<NTE>
<xsl:apply-templates/>
</NTE>
</xsl:when>
<xsl:when test="name()='DG1'"/>
<!--<DG1>
<xsl:apply-templates/>
</DG1>
</xsl:when>-->
<xsl:when test="name()='OBX'">
<OBX>
<xsl:apply-templates/>
</OBX>
</xsl:when>
<xsl:otherwise>
<xsl:copy-of select="."/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>

Answer 1

I would suggest to write code like
<xsl:template match="a:OBR/*">
<xsl:choose>
<xsl:when test ="name() = 'OBR-10' and string-length(.) = 0">
<OBR-10>USER</OBR-10>
</xsl:when>
as
<xsl:template match="a:OBR/OBR-10[string-length() = 0]">
<xsl:copy>USER</xsl:copy>
</xsl:template>
or perhaps
<xsl:template match="a:OBR/OBR-10[. = '']">
<xsl:copy>USER</xsl:copy>
</xsl:template>
that is, to write templates that match each element by its name and if needed a predicate/condition instead of that odd approach to match on * and then test the name. I don't see that necessarily as an optimization (you would have to measure with a particular implementation) but as a clear and modular coding style.
The
<xsl:otherwise>
<xsl:copy-of select="."/>
</xsl:otherwise>
would then be code as
<xsl:template match="a:OBR/*">
<xsl:copy-of select="."/>
</xsl:template>
or probably already covered by an identity transformation template set up as the starting point to initiate and keep up the processing.
You would have to show the namespaces in the input document and the XSLT to allow a precise suggestion in terms of namespaces (could be that you want/need xsl:template match="a:OBR/a:OBR-10[string-length() = 0]").