For those of you interested in iOS devices supports these latest "advanced" features, here is the document to read.
https://support.apple.com/en-us/HT202628
Below is a copy of their page, saved here in case it is removed.
iOS supports optimized client roaming on enterprise Wi-Fi networks. The 802.11 Working Group standards k, r, and v let clients roam more seamlessly from access point (AP) to AP within the same network.
802.11k
The 802.11k standard helps iOS to speed up its search for nearby APs that are available as roaming targets by creating an optimized list of channels. When the signal strength of the current AP weakens, your device will scan for target APs from this list.
802.11r
When your iOS device roams from one AP to another on the same network, 802.11r uses a feature called Fast Basic Service Set Transition (FT) to authenticate more quickly. FT works with both preshared key (PSK) and 802.1X authentication methods.
iOS 10 includes support for adaptive 802.11r on Cisco wireless networks. Adaptive 802.11r offers FT without the need to enable 802.11r on the configured Cisco wireless network.
802.11v
iOS supports the basic service set (BSS) transition-management functionality of 802.11v on certain devices. BSS transition management allows the network’s control layer to influence client roaming behavior by providing it the load information of nearby access points. iOS takes this information into account when deciding among the possible roam targets.
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.
Learn more
Most Wi-Fi network hardware vendors support 802.11k, 802.11v, and 802.11r (FT). You need to enable and configure these features on your Wi-Fi router before your network can use them. Setup varies, so check your Wi-Fi router's manual for details.
The lists below show which iOS devices support 802.11k, 802.11r, and 802.11v. To use 802.11k and 802.11r, you need iOS 6 or later. To use 802.11v, you need iOS 7 or later. To use adaptive 802.11r, you need iOS 10 or later.
802.11k and r
iPhone 4s and later
iPad Pro
iPad Air and later
iPad mini and later
iPad (3rd generation) and later
iPod touch (5th generation) and later
Adaptive 802.11r
iPhone 6s and later
iPhone SE
iPad Pro and later
802.11v
iPhone 5c, iPhone 5s, and later
iPad Pro
iPad Air and later
iPad mini 2 and later
iPod touch (6th generation)
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If you like to play around with these new WIFI standards to get faster roaming and efficient use of access points in a multi-access point setting, the cheapest way I can find in terms of access points supporting these 802.11k and r protocols is the Edimax CAP300 for $50 per access point. However, given that this AP can only do the 2.4GHz, I recommend that you get at least a pair of the CAP1200 to get both the 2.4GHz and 5GHz and AC speed.
More info on this:
https://www.smallnetbuilder.com/wireless/wireless-howto/33045-how-to-get-fast-reliable-wi-fi-roaming
http://www.edimax-de.eu/edimax/mw/cufiles/files/faq/SMB/022_How_to_Configure_802_11r_and_802_11k_Under_AP_Controller.pdf
