In the scenario I suggested, a switch connected to the home plug with the three devices and the 582 plugged into that. Connecting at te switch rather than plugging them all into the router will minimise traffic and switching.
Yes, functionality could be lost. For example: something like parental controls (or another function) , they need to be implemented in the router that is connected to the modem. So if the TP-link was purchased because it offered capabilities that the 582 did not, then they would be lost.
M H C
taurus excreta cerebrum vincit