Can the SILO feature be used for separating the environments in Big IQ?

I had the same doubt. But different F5 articles address this point: Silos are not intended to separate enviroments:

https://cluddocs.f5.com/training/community/big-iq-cloud-edition/html/class6/module5/module5.html : Starting with BIG-IQ 7.1, you can now import devices with object naming collisions into a temporary “silo” on BIG-IQ. Think of this as a quarantine area that doesn’t impact the rest of BIG-IQ or overwrite shared objects which may have different configurations on other BIG-IP’s. This will allow you to rename the configuration objects on BIG-IP using BIG-IQ. Once all of the conflicting objects that need to remain unique have been renamed, the device can be re-imported fully into BIG-IQ without the need for a silo.

https://clouddocs.f5.com/training/community/big-iq-cloud-edition/html/class6/module5/lab2.html : Silos are meant to be temporary so that an Admin can view and then resolve conflicts,. The ultimate goal is to be able to resolve any conflicts from BIG-IQ and then remove this device from its Silo, and eventually re-import back into the default Silo.