Have default optional rules changed?

[dto]

Have the default optional rules in PzC changed? Looking at the standard Bulge campaign in Bulge 2.0, the Alt Fire options are recommended, as is Delayed Disruption.

Is there a reason for this? In particular, I'm wondering which options are there strictly for realism (Delayed Disruption) and which actually affect play balance? For example, would including -- or not including -- Alt Fire rules in the vanilla Bulge campaign change the play balance? Are the scenario designers actually recommending that Alt Fire be included?

Michael