Two 32nd beamed in FInale exports like this:

<note default-x="111">
<pitch>
<step>F</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>32nd</type>
<stem default-y="10">up</stem>
<beam number="1">continue</beam>
<beam number="2">continue</beam>
<beam number="3">continue</beam>
</note>
<note default-x="128">
<pitch>
<step>F</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>32nd</type>
<stem default-y="8.5">up</stem>
<beam number="1">continue</beam>
<beam number="2">continue</beam>
<beam number="3">continue</beam>
</note>

In MuseScore r2681, only one beam element is exported with number one.