That's a completely different can of worms. NXT as a platform has integrated versions of almost every major feature any crypto has released over the last 2 years with varied results. I will be honest and say that I haven't had time to fully look into Ardor, but while it is offering one solution to the problem of easy, deployable blockchains with it's child-chains system, I think it will require more research to determine the differences. I'll try to find time to do a little more research and see if it warrants an analysis. Thanks for the comment!