Here are a few of my favorite questions posted on our wall @ Ignite.
In 7.x, can I set URL blocks to critical rather than informational so my SIEM can see "critical" drops?
No! But you can use the new log forwarding filter in PAN-OS 8.0 to solve your problem.
This question was posted several times and occasionally pops up on the discussion forum as well. Before PAN-OS 8.0, the log forwarding feature wasn't very granular and most of the time you’d end up with a flood of unwanted logs that you still have to filter through manually.
With PAN-OS 8.x, you can build a filter for log forwarding in a similar way as in the monitor tab.