I'm trying to look at how space engine generates stars, and I'm a bit confused by a few things. For instance, for Y type stars, the spectral class seems to have no effect on the absolute magnitude or the temperature, while it does for other stars like G stars. Also, most values seem to go up lineally with the different spectral class numbers, but at round numbers it gets kinda wonky. Look at O9.9V, down to O9.1V, then look at O9.0V and see how it doesn't match up. I'm wondering if this was done on purpose because of something I don't know about, because I am trying to make my own star generator atm, which generates values starting from a spectral class.

Some stars do not even fit into a spectral type- there is one star that has characteristics of four different spectral types!