Power management still depends on knowing your clients Tx power since no standard excists for aligning this in regards to two-way wireless communication like colaboration. Having a single AP transmit at highest regulatory power level might ruin transmissions. DTPC is proprietary and therefor only works for CCX capable clients. Maybe an algorithme looking in to the retry rates seen from clients and APs could solve that within an AP group. Performing a manual RF channel plan still optimizes airtime better in high density environments. But one could use wlc channel planning as a start since optimizing for 802.11ac require more cell tuning for the high MCS rates.