height difference seems more fit for the r34 tag meaning also, does penis size difference apply to yaoi or is it general?

the description could be something like "Size difference between characters" or potentially could also include difference between the penis and the other parties body

It is helpful since monsters include just even tiny stuff or straight up humanoids that are said to be succubuses but have no difference

Maybe it should be called height difference instead?

I might not be very familiar with the rule 34 site, but I can't find the description. Anyway to me it sounds like it would be confused with penis size difference or even breasts