I dirty flashed on top of existing install, Hyperdrive install script prompted me to wipe cache & dalvik, which I did, & chose the standard TW theme, not red or blue, & made sure to choose the AllShare app & voila
Screen Mirroring worked.
I'm guessing that my prev version of the supporting app got corrupted somehow… thanks again to all for sharing!
Samsung Galaxy S4, Root De La Vega, SafeStrap 3.65 & MI1 Modules (thanks, Hashcode!), HyperDrive 10.2 (thanks sbreen!)
New to Sammy, not rooting & custom roms; but I still need & want to learn more!