You are so right about it having a habit of changing.. I got my first CH when I was 23 (I am now 62), and it has changed and morphed over the years.
I just started the vitamin regimen in 2016, had no cycle at all in 2017-2018, had a light cycle of "shadows" in 2019, I am now at "what I hope" is the end of a cycle that started early December 2020... Even though this has felt like a full cycle in frequency, it is much lower on the pain scale, and they are not lasting as long.
I really hoped when I went the 2 years PF, I was going to be one of the lucky ones that would never have one again, but I keep telling myself they are not a fraction of the pain level I am used to, and they really shorter, The first thing I do when it starts is look at the clock, have been for years.. and I watch A LOT less of the clock these days
Good Luck!!!!!