In 3.5e, you can handily sidestep this problem as I did with my Advanced Being Framework. Essentially, the prospective advanced being selects the type they want for their metamorphosis. The main thing is whether it is a defiler metamorphosis or a preserver metamorphosis. And no longer is “dragon” type evil for some reason.
And -
So like you said, we have advanced beings. There is a metamorphosis but they metamorphose according to their individual preferences. So you can have an avangion dragon, and a ravager fey, both advanced beings, categorised by their avangion or ravager advanced being status, not by their type.