Cheran Cheguttuvan, built a temple for Kannagi. By any chance this temple is Kodungollur Bhagavti.
Kodungollur's earlier name was Mahodayapuram. The capital of Chera's. But, the capital of earlier chera's was Vanji, present days Karuvoor or Karur. So, to my humble knowledge Cheguttuvan constructing a temple for Kannagi, at Mohodayapuram could not be justified as Kannagi was from chola country and her connections to Chera country could not be established, except Ilangoadigal chose to write 'Silapdhigaram'.
But, I have listened to songs on Kodungollur Bhagavati, that repeatedly chants 'Kannagi Kannagi...'.
I recollect an article on "Om Shakthi" magazine (early 90s) linking Kannagi with Kodungollur Bhagavati.
The author of that article had given multiple evidence to relate this temple with Kannagi.
1. Some traditions during temple festivals with Gold-smiths. 2. He stats an hidden room in basement behind Bhagavti temple and that is opened once in a year for some puja. etc.
Since I had read this article long time ago, could not recollect some thing more here. If any one read this article or know something related to this.