Hi, yes worth buying if you don’t have vvdi-prog, it does not fix anything, its just a programmer with read / write functions. All fixes / mods to files you need to make yourself or write scripts ( similar way of UPA )
Depend of scope, if we talk regarding ecu programming KT200 cover also obd2 and many other types of ecus ( denso models, jtag, bdm ) if you need also programmer for MCUs and other modules then Multi-Prog.