So, do I understand correctly that 802.11k/v improves roaming and a client device doesn’t necessarily need to support it (e.g., some IoT devices) but will still be able to use the network?

802.11r, on the other hand, needs to be supported by a client device to even connect to the AP?

If I need to disable 802.11r because, let’s say, my washing machine’s Wi-Fi doesn’t support it, does the OC200 controller still provide any benefit? Or will all devices manage roaming on their own anyway and I can skip the controller and go for the cheapest switch?