The reason you haven’t seen an install like that is because it’s prohibited by Tesla. In the Powerwall 2 install manual it says that a Powerwall can be installed no more than 39.5” from the ground to the bottom of the unit. Since the Powerwalls themselves are more than 39.5” tall that means you can’t install them like that. Now, whether that will ever come back to bite the OP, I don’t know, but it is worth knowing that the install is not ‘legal’ according to Tesla. I would think the only time it might be an issue would be if warranty work needed to be done by Tesla.
The manual is available here:
https://www.tesla.com/sites/default..._2_AC_BU_NA-EN_Installation_Manual.pdf#page34
And the limitation is here:
View attachment 583392