Hello Aviv,
Question 1 answer:
Select Shutdown feature run interval is set in "frequency" parameter under "select shutdown" in Smart RF policy.
There are two thresholds : "cci-high-threshold" and "cci-low-threshold" where CCI stands for Co-Channel Interference.
Every time Select Shutdown is run, the CCI interference is calculated. If it is found to be higher than the high threshold, one or more 2.4GHz radio will be mapped to SSD_Hidden. SSD_Hidden is a special wlan that users will not be able to associate to. The radio runs in the background to continue monitoring the environment. For this reason, the radio state will not show as "Off", but rather, "Hidden".
The next time Select Shutdown is run, if the RF environment situation change and the average CCI falls below the lower threshold, the algorithm considers "Awaken"ing previously hidden radios. It does so by selecting the ones that will cause the least CCI to its neighbors. It continues to do so until CCI is estimated to cross the lower threshold but not the higher threshold.
References:
https://documentation.extremenetworks.com/WiNG/5.9.2/WCSRG/WiNG/GUI_Reference/topics/t_configuring_s...
and here: page 1643:
https://documentation.extremenetworks.com/WiNG/5.9.2/CRG/9035491_WiNG_5_9_2_WC_CRG.pdf
Question 2 answer:
Smart RF is not currently utilizing radio resource measurement reports from clients.