Danz,
The Spike software allows you to configure the spur reject mode, as well as change RBW / span. Unfortunately, these are the only tools we have for the SA124B when it comes to spur mitigation.
You can look at the SM200A. If you require better spurious performance than the SA124B offers, this would be the next step. It is also much, much better at capturing periodic bursts of energy.
