As has been mentioned elsewhere, there is indeed a whole world of ballroom dancing, and in that world, top class competitors would barely fill a small town.
We are discussing the technique as currently published by the associations and as required for their professional exams, which IIRC is what Interested is preparing for. As and when the books are updated then some of the things seen in competition may be included. The top competitors can, and do, deviate from standard technique but they know how and why they are doing it because they have a good understanding of the basic theory. Very often these deviations are used by less experienced, lower level competitors and can look truly awful, sometimes prompting comment from senior adjudicators.
Top competitors very rarely dance a basic chasse in chacha. Almost all the variations they use instead require the use of ball-flat, ball, ball-flat footwork so it is no surprise that they find it strange to use the standardised footwork for a chasse. In the Innovation video, Karina acknowledges the standard footwork and explains they use different footwork in competition so that they can play with the timing and dynamics of the figures. That does not mean it is appropriate for everybody.
Finally, I do keep up with what is happening in dancing at all levels not just competitive, using all the facilities available to me including books, videos and congress lectures. It was interesting to note that my method of counting chacha, 1 2 3 cha cha, was presented at a popular teacher traing session in Italy last year. I'm not suggesting that they copied one of my lectures

but I like to think we both developed the same idea from basic principles.