LCMC is small because it was designed as a Chinese match for FLOB.
We have now completed a sizeable balanced corpus of spoken and written Mandarin amounting to 50 million words (over 70 million Chinese characters), which is used in the Routledge Frequency Dictionary of Mandarin Chinese. The corpus is not currently open to the public.
Obviously,according to Xiao, it is for the compilation of the Rougtlege Frequency Dictionary of Mandarin Chinese, not a counterpart of FLOB.I guess it won't be available to public earlier than the issue of RFDMC.
hittle2008 is right - it does not model FLOB. The corpus is a colletion of texts from four registers: spoken, fiction, non-fiction, and news.