Lake

Siren Mastery adds a different level of control to the sirens, and it allows more variations in vehicles and the number of sirens in those vehicles. But if you aren't too fussed with that, then ELS works fine as you can switch between sirens at will just the same as with Siren Mastery, which for the most part is all I use it for. And yes ELS does have controller support, information for it can be found in its documentation when downloaded.

I'd recommend double checking you have installed everything in the right way/correctly. Also, you should have (as with installing any mods) made a backup, so if all else fails, use that and try again. I'd also see if you can use ELS in the vehicles in a clean save, perhaps your save has something to do with it - it's worth a shot regardless!