I suppose you forgot about the late 1990s then. that was when virtually every CHR-Mainstream in the USA was all Modern, all the time!
I mean, of course they were not Modern AC, however just like during the very early 90's, almost every CHR was highly Dance/Rhythmic, with a handful of regular pop/rock hits still blended in for good measure. Do you remember when CHR did not want to touch Nirvana's mammoth hit back then?
I have considered WXKS-FM a fully balanced CHR since the start of the 2000s.
Was your first paragraph meant for me? I said that CHR is mostly rhythmic, which I stand by. It had nothing to do with being being modern or not. We are in agreement that it's modern/current. Also, a date of January 1995 was stated. My point was Kiss 108 did play some rock songs before that date. "Some" is the key word. But my first reply acknowledged that they played rock songs (yet, not many at all) even before that January 1995 date quoted.
Regarding it being balanced, I disagree. Adding a Blink-182 songs into the mix in the late 90s doesn't change that it still was mostly rhythmic based songs on the station. That was the same era where boy bands and Britney Spears rose to dominance. To me, the pop/rock sound that broke through wasn't dominant. It was more of a niche fringe from the alt-rock movement that passed us like Haley's Commet. Just like how Green Day will pop their collective head up like gophers once in a blue moon on CHR. Outside the alt-rock bands, it included ballads from bands like Nickelback and The Goo Goo Dolls, who completely changed their sound to lean into Top 40. Still not rhythmic, so it supports your perspective. Again, I don't see it as balancing, and pop/dance songs were and are still dominant on CHR.
I far from see it balanced today. We bring up modern rock, and people basically say that it's dying. They say that people today like rhythmic music. Modern alternative is rhythmic much like alternative's origin. We say that Alt-rock was a niche fringe of alternative that has wained. Modern rock is mostly relegated to HD-2, Satellite, and Internet. The stations that play it on analog frequencies incorporate classic rock songs into the playlist. With all of that, to then say the CHR is balanced is a statement that is difficult for me to agree with.
CHR is designed to play what is Top 40. And, Top 40 will include pop/rock songs, but I see that is not even close to where I would call it a blend. It's mostly rhythmic sounding music. I would set the overall default 70/30 (arbitrary number depending on the year) as to the balance of rhythmic to non-rhythmic songs (not necessarily pop/rock) on CHR. When teasing it to strictly pop/rock, I would set that arbitrary number to 80/20 overall, depending on the year. Lately, I would see that as possibly less. Early 2000s with the Blink-182, Barenaked Ladies, and Fall Out Boy influence, I would say that it was possibly greater for that period of time. I still wouldn't say it's balanced.