I would say to start with the features Apple outlines here: https://support.apple.com/en-us/HT202628
(AFAIK, 802.11k is in 7.4 on wifiwave2 routers for 2.4GHz to 5GHz roaming on the same device. Is it implemented for routers/AP's on the same LAN? If so, do they have to managed by the same CAPsMAN instance?)
Apple calls out these pieces of 802.11v:
DMS would probably be lower on the priority list, since most in-home multicast traffic is simply devices advertising themselves for things like AirPlay, Chromecast, etc.802.11v
iOS, iPadOS, and macOS support these 802.11v functionalities on certain devices:
BSS transition management with Disassociation Imminent allows the network’s control layer to influence client roaming behavior by providing it the load information of nearby access points. The device takes this information into account when deciding among the possible roam targets.
- Basic Service Set (BSS) transition management
- Disassociation Imminent
- Directed Multicast Service (DMS)
- BSS Max Idle Service
DMS optimizes multicast traffic transmission on wireless networks. The device uses this information to enhance multicast communication and preserve device battery life.
The BSS Max Idle Service helps clients and access points efficiently decide how long to remain associated when no traffic is being transmitted. The device uses this information to preserve device battery life.
When you combine 802.11k and 802.11v’s ability to speed up the search for the best target AP with FT's faster AP association, apps can perform faster and you get a better Wi-Fi experience in iOS, iPadOS, and macOS.
I, for one, would like to be able to install one, two, or three hAP AC2/3's or AX2/3's in someone's home and have devices intelligently roam between each router's 2.4 or 5GHz radio, and have the AP's be more actively involved in pushing clients to the 5GHz AP. The complaints I often receive are "my TV is buffering" because every device in the house jumps to 2.4 and won't "stick" to the 5GHz AP. Creating 5G-only SSID's is an ugly bandaid.