There is a way. You can either create a s3tbx.properties file in the etc folder of the SNAP installation directory and add the property s3tbx.reader.olci.pixelGeoCoding=true.
You can specify this also on the command line. Then add -Ds3tbx.reader.olci.pixelGeoCoding=true to the call.
Similar properties are:
s3tbx.reader.slstrl1b.pixelGeoCodings
s3tbx.reader.meris.pixelGeoCoding (for upcoming MERIS 4th reprocessing in SAFE format)