LTM V11.3 VE Factory Reset

i am not aware of command to reset all bigdb keys in 11.x but there is reset-to-default option to reset each bigdb key.

sol13455: Overview of BIG-IP logging BigDB database keys (11.x)

if it is okay to retain mgmt ip and bigdb keys, tmsh load sys config default may be usable.

sol13127: Restoring the BIG-IP configuration to factory default settings (11.x)

otherwise, installing software in a new slot without importing existing configuration or clean installation may be a way.

sol13438: Controlling configuration import when performing software installations (11.x)

hope this helps.