I believe those ears on the 21.5 battery case were intended for a center stand. The battery case was redesigned at some point in production eliminating them.
I managed the conversion of some EsseEsse9 bikes for police use. In addition to outfitting the bikes with an emergency lighting system they requested center stands. We worked with a local motorcycle fabricator named Todd who runs Sonic Moto to design an build the stands. He was planning on producing the stand for sale but I have not heard an update on the project. It's a really elegant solution that uses the 4 mount points the rider foot pegs attach to.
For the Experia the stand was fully engineered and a small batch was produced. Suspect the financial situation played into the part not being put into full production.
I have not seen one in person but a number of Experia that were built for police use had them installed. There are 2 mount points located on the motor case
