The system driver isn't allowing any change to the siren default sound, or any other siren parameters via Rule Machine:
I would suggest adding a setParameter custom command so that all the features of the device can be changed programmatically.
Unfortunately, @jtp10181 apparently isn't in the HE driver biz, at least for now. 
The “siren” command doesn’t have any parameters. You need to change it in preferences page.
Play sound DOES take a sound parameter.
Neither does strobe.
Thing is, for example, you change siren to loop continuously in preference page, which may be good for a smoke detector, for example, but then if you want it to just play a discrete sound file, it'll again loop continuously. There's no way to change parameters on the fly. Or you want to change the sound from smoke to co? Much need exists.
Another example, without looking hard, would be the led colors. Wouldn't it be nice to change them with a rule? I don't even think you can flash the strobe separately from the siren.
Perhaps I'm missing something and there's (another) driver wizard in web land who's written something. Or it may be time to look into Home Assistant. I wonder if the integration with Hubitat is local? Network? There's always an AI robot. Argh.
Sure would be nice to get some of these things to work. I posted this when it first came out.
I saw that.
Any day now….
That is partially on the device. The strobe and siren are tied together. The only way to strobe without sound is to adjust one of the settings so no sound plays (I forget which one), or to have a blank audio file as one of the tones. The blank audio file would be better because changing multiple settings every time is slow and error prone.
Sounds like this device currently has better support on SmartThings than Hubitat 
I would rally on Zooz about the poor feature support and they can either put pressure on Hubitat or commission me to make a better driver. Maybe start a thread in their community? Or open a case with them and explain what you are trying to do on Hubitat.
Yeah, that's how I'm handling my alert/notification setup, and it works fine.
Unfortunately, you're stuck doing that with just one color (since there's no way currently to change colors via automation), but I really only have one use case right now anyway.
It would be nice to be able to use other colors for other alerts/notifications, so hopefully that capability comes someday. Until then, it is what it is.
@agnes.zooz Can you take a look at this thread for possible enhancements to the ZSE50?
Zooz has not been as active on here, hence 
I opened a case and got a response from Sara.
It's a Catch-22 situation.
Thank you for reaching out!
In some cases, a community-developed driver may be available to unlock additional features on Hubitat. These drivers are created and maintained by members of the Hubitat community, not by Zooz. If you are interested in exploring community options, we recommend checking the Hubitat forums for the latest information and user-supported drivers.
We work with all of the platforms to provide thoughtful integration for our devices, and Hubitat has integrated the ZSE50 and it works in our testing. While the most open platforms like Home Assistant or Z-Box allow for full functionality out-of-the-box, other platforms like Hubitat often require dedicated custom code for expanded functionality of Z-Wave devices, even though it's a standardized protocol that natively supports all functions of a Z-Wave certified device. If a feature is not exposed in the native integration on the platform, please let Hubitat support and our team know so we can work together to add it based on your feedback. We aim to support as many platforms as possible while balancing development costs and keeping device pricing reasonable. Customer feedback helps guide where we invest in additional platform-specific work.
Best,
Sara
Zooz Support Team
edit: Not surprisingly, a canned message. Is "Sara" even a real person any more?
Au contraire.
Change parameter 1 to 4.
firmware 1.3
Still can't change it, or others on the fly. In Hubitat.
edit: I guess your workaround to do it on the fly is to set volume to zero, which you can do programmatically.
In link below, guy wanted to silence siren while strobe continued. While he was able to change parameters on the fly via HA, the pause was unacceptable. I'd settle for a pause any day, for changing sounds, sound behavior, colors, etc.
They are bagging on Hubitat due to its restrictive driver model.
Did you do this part? Not sure what you sent them but they want you to ask for specific things.
I have spoken with a real Sara who works there, regarding drivers, so probably.
I sent a link to this page yesterday to someone else at Zooz who wrote me an email. Claimed the link didn't work and wanted me to regurgitate the issues. Wasn't in the mood. I didn't take it as a good sign that they couldn't figure out it was their firewall. Maybe I'll regurgitate it today.
Sara may have once been real. When was the last time you spoke to her, lol.
Hubitat puts out incomplete drivers. Zooz won't build their own. Customers left in lurch. Doesn't seem optimal for anyone. Seems like there's a fairly obvious fix, but nobody seems to want to go down that path either.
Well it started out making Hubitat drivers for fun, I wanted them for my own purposes but also wanted to share them with everyone. I was using all the devices in my house. I was not fond of the existing custom, or built in drivers, so I wanted to see what I could do.
Many of the newer devices I am just not using in my home so there is not a huge motivation to make custom drivers. The challenge of making the best option has worn off. I now also have lots of side projects that pay me for my time.
I am not leaving forever, just working on other things right now.
I wouldn't have necessarily gone the Zooz route if it weren't for your drivers. And, bear in mind I replaced all my stuff, mostly, with LR. The setParameter command (also give thanks to @JasonJoel for similar Jasco effort) is awesome to set led colors on my Zooz toggle switches.
I just looked into HA, a tad. Not an easy thing to get started, even from the base hardware/operating system, never mind programming. They recommend 2 gig memory. A P-5 in a box for 200 bucks I saw comes with a 40w adapter and a fan! A fan! I don't think any circuit board work is required. Even the Green is 200 bucks. Then you need to buy Zigbee and Z-wave radios. Then the radio thing I saw does either Zigbee or Thread, but not both at the same time. Oy. From the frying pan into the fire.
Download the Hubitat app
