Cross platform works just the same as the Windows one but steamlines alot of stuff, for example you no longer need a taxonomy, it is inferred from the DU Project you connect it to, which is generally very very nice.
I don’t have an on-prem instance where I have the Document Understanding Center and AI Center enabled to check, but provided its up to date I am not aware of a technical limiation that would stop you. If you have the DU center and can make a project and deploy a skill, it should be available in the dropdown when you try the cross platform activities.