Multi Partition ASM Question

Partitions are a concept of segregating virtual servers and other objects but it does not segregate many items such as the attack signature database.

Being that you are on 11.6, the following is true:

https://support.f5.com/csp/article/K8217

When signatures are updated in BIG-IP ASM 11.0.0 and later, new signatures are placed in staging (non-blocking) where as updated and unchanged signatures remain in the configured mode (blocking).

So to reiterate, your only danger is attributed to the updated signatures causing false positives. You don't have to worry about the brand new signatures as they'll be put into staging.

Ensure that learning suggestions aren't disabled (auto or manual will work) and be ready to resolve those false positives.