it has layer management within it, does that not have some help files/pages on layers and possibility of creating a layer set?
it also has object management for more 3d type stuff but that might not help?
remember that Xion has been designed with PS7, so other image editing software should comply with Photoshop rules/layers in order for you to create layer sets
if its for creating vu's and you don't have layer sets as an option then you could use the layer based approach with the respective keywords, a workaround for not having that feature
for general neatness of the layers etc its great to put them into sets to reduce the layer stack but not essential
for utilising some of the toggle type features then layer sets are the only things you can use although you could workaround those by showing/hiding layers based on which button/mode is pressed to simulate the toggling
as skry said PS is the way to go, we all tend to use it as it is the industry standard and pretty much the best there is, anyways...
we won't go into the why of using anything else anymore but as long as it supports psd format for the now then hopefully it should support layer sets, if it doesn't then your going to have to workaround those issues or buy PS
I'd hazard a guess that they most likely wouldn't have left layer sets out considering all the other stuff it does, as no-one here really uses PhotoImpact your best initial hope for anything relating to the way it works is its help pages to guide you, we can only offer the main ways PS does things or try to be generic in somethings
hope some of the above helps tho
