Hello vertigo58,
Thank you for your feedback! I have passed along your suggestion to include an in-app message notifying users if splats are unavailable on their device.
You are correct in that the iPhone XS does not support splats; the iPhone 11 is the oldest iPhone that can use this feature. Our FAQ section contains information regarding compatibility and other general questions, and you can find a list of supported devices for splatting in the section here.