The latest LM465s with Soft Start should flash fine, when the security console is triggered.
I tested some earlier soft start LM465s {Date Code 08A01}. They did ramp up and down and not flash.
A later revision firmware LM465 {Date Code 09J44} will flash with the consoles trigger.
So how they act with an alarm is depending on when it was manufactured.
Before Soft Start and later revision Soft Start lamp modules should flash On and Off.
Early Soft Start will ramp up and down and not flash correctly.
With a standard X10 On or Off. All soft start lamp modules should ramp up and down at about a two second rate.
The difference between early and later revision soft start modules, is how they handle the All Lights On, All Lights Off, All Units Off commands and a fast cycle of On Off commands.