IEEE 802.11r/k/v

I have a linksys wrt3200acm and also a netgear wndr3700v2 that I am planning to load OpenWRT onto in order to use 802.11r protocol (I use Gargoyle right now). Are there any hardware dependencies on the router I need to worry about when considering to use OpenWRT and 802.11r, or do I just need routers that are supported at the current firmware versions of OpenWRT (both of my routers are as best I understand).

Another question is, if I use 802.11r and I have a 3rd router that does not support 802.11r and I give it the same SSID and password as the 802.11r routers, will there be any downside except perhaps losing connectivity during the cut over?

Sam question for 802.11k, or 802.11v - though I suspect adjusting power of a radio may yield a different answer than 802.11r protocol.

Thanks in advance!