I had not thought of it in that way really.....i suspect i would just put them all in a fast action high detail mode just to keep things uniform? I do get the point that some movies look way better in perfect 4k compared to some others that look ok in 720p...and i do agree it varys from movie to movie...i might prefer a simpler do them all the same approach? but maybe
Yeah, constant quality is the way to go if you are saving digitally. That way you are not wasting bitrate on scenes that don't need it and ensuring good quality on more demanding ones.
If you are burning to a dvd for use in a camper or something, constant bit rate is probably the way to go as you can fill the disk for highest possible quality with minimal guess work. Useful if you want to get all the Minion movies on one desk for use in an infotainment center.
You just have to factor that transcoding back to dvd does add space.