Yup he was comfortable in his own skin at UCF (the way Rhule is wherever he goes), and at NU he clearly felt like he had to fit inside the boxes just like you described. And it broke his brain when it didn't work haha.
After 5 years I still never felt like I knew Frost's personality or values or likes/dislikes or any of that, other than the coachspeak he would drone out in monotone press conferences. The only time I ever felt like I was seeing the "real Frost" was in 2017 when he was at UCF, and especially in their behind-the-scenes YouTube series. I was so hyped to have that guy here, and he never showed up. NU Frost just had his head in the clouds.
I don't know how much sympathy he deserves, obviously he got paid a ton of money to faceplant spectacularly and obviously he was neglectful at best when he controlled the program. But especially seeing that new quote, it's pretty clear that he never wanted this job, he just felt insurmountable pressure to take it, and he destroyed his career because he had no idea how to handle it.
Someday after like a decade has passed and we're awesome at football again, if Frost figures out how to be humble and reflect on his shortcomings, it would be really interesting to hear his take on it all.