The Xantech 232 router has 422 or 232(not both) for the input and 4 422 rj45 outputs and 4 232 9pin outputs. So no need for the 422/232 converters unless you're going further than the 232 will work distance wise to the device to be controlled or need more than the 4 9pin 232 outputs.

The splcd's are not 2way so they don't work real well for security to provide feedback of open zones or alarm status. They do work great for lighting and a/v though.

To answer your original question, I haven't done anything with the K4 but have done several of the splcd's and as long as you have current firmware/software, they work great.