There is a new question that has been tagged with size. There are about 7,000 results for posts that mention the word size. There is a more specialized tag called size-scaling that currently has 12 questions to its name. And there is this old Meta Q&A about introducing a [tag:creature-size], that was declined (with few votes margin and a total score of 5) on the grounds that it was "too narrow" and therefore not useful.
How about making size-scaling an alias for size, which appears to be a relatively common kind of question, and which would be a bit broader so it also can support creature-size questions, and other size-related questions? Most I have seen have to do with space needed, or reach, or aura sizes for increased sizes of PCs, which is not exactly what size-scaling is about: that is more about how to deal with situation where a gargantuan creature interacts with a diminuitive one, if I read the description right.