ShapeTag (can adjust imageQuality to match liking, note that at 100 filesize is massively increased):
XML
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<TranscodePresetDocument xmlns="http://xml.vidispine.com/schema/vidispine">
<name>webp</name>
<format>webp</format>
<audio />
<video>
<scaling>
<width>512</width>
</scaling>
<codec>webp</codec>
<imageQuality>85</imageQuality>
</video>
<metadata />
</TranscodePresetDocument>