What does the sliding power setting in BLE and VBLE equate to?
Where can I change BLE and VBLE power settings?
Access Points → Select AP → BLE Settings/VBLE Array
NOTE: Make sure vBLE Engagement is enable under Bluetooth based Location Services in Site Configuration
Should I change BLE and VBLE power for all APs?
Only on rare occasions is it nesscary to change the BLE/vBLE power. If needed to change the BLE/vBLE power, for location purposes, it is highly recommend to change BLE/vBLE power for all APs at once if necessary.
Access Points → Bulk Select APs → More (Top right of the page) → Batch Edit → Set Beacon Power (Change via the slider)