So no surprises here that this thread has fizzled out since the release of ELS V, however I'm just going to drop one last gem here.
This is a quick trial model I made for my latest and last version of Aussie Flash Patterns, a simple carcols.ymt edit. I created another entirely new flash pattern to it that sets sirens 2-20 as rotators, varying in colour, direction and start position. Siren 1 is to be used as a clear box to put around the rotators, hiding the emissive texture. When turned on, siren 1 expands by x200 (from a low axis point), while the rotators spin. The beauty of it is that it can be used flawlessly with ELS, giving you more rotators and saving you from using up an extra slot.
Release is expected to be shortly...ish