Maybe you're thinking of someone that said you could use cboot2 on newer Wii's or something?
If so, that's something entirely different and has nothing to do with boot2. On that note, why was it named that in the first place? Why not something more fitting to what it does like bootfrii or something of the sort?
Anyways, you can't change the fact that you can't install bootmii to boot2. If the hackmii installer says you can't, that's that. It's not happening.