Kundalini and Chakra supplement each other.
Chakra meditation is not like a type of rocket science. Kundalini is awakened later on, first chakras become opened up. I think, Chakra-opening is not experiential just like opening of a door. Focused mind on kundalini at chakra is called as chakra opening. Focusing should be pin pointed and the kundalini should be appearing as brilliant/blissful. This much strong focusing does not appear possible without the additional help of sexual yoga, especially in today’s materialistic world. Symptoms of the chakras opening up and Kundalini entering the brain-chakra are as follows. There is intermittent feeling of upward blasting type of pressure inside the head that appears heavy. There are tremors/trembling in the body, especially in the hands (more of so in left hand). The mind is blissful, especially at beautiful and natural places. A blissful and attractive attention on kundalini is built up itself, especially at beautiful natural places. There are symptoms of occasional headache, tiredness, calmness and interesting Yoga postures happening itself with mind well focused on the Kundalini image. These symptoms are also produced through the strong non-dual attitude. Kundalini is strengthened spontaneously with a non-dual attitude. At these above times, kundalini awakening can occur at any time or place, especially if kundalini gets a suitable stimulus in a surprising way. Stimulus may be there like the following. If a man is worshipping God Shankar as his kundalini and that God Shankar has entered his brain-chakra, then pilgrimage to the places favorite to Shankar would be the good stimulus for the kundalini to be awakened. That place may be Mount Kailash or Kashi Vishvanath. It is just for an example. The similar phenomenon had happened with Premyogi vajra too. He had the image of that spiritual old man in his mind as his kundalini. That had entered his sahasrar (top) chakra with help of one yearlong kundalini-yoga including last month of tantric-yoga (sexual yoga). At that time, he got an opportunity to attend a ceremonial function at the home of his relative brother. He was meeting after several years. In past, he used to be friendly with Premyogi vajra. He was in a close relationship with the physical form of his kundalini (means that he was once closely related to that spiritual old man). That was a right stimulus for his kundalini. That caused awakening of his kundalini.
Mere activation (not opening/awakening) of chakra probably means that the blood supply to chakra has increased, but without a being focused kundalini image there. Instead, chakra is having variety of mental thoughts or images. It leads to paranoia only, because there is not any kundalini upon chakra. It is the kundalini that controls the monkey- natured mind. The Kundalini also protects from the side effects of sexual activities. These are like the drainage of sexual energy to outside, oscillation/paranoia of mind etc.