It's 64x64 AVB streams nowadays and you can route any bank (8 sends) to additional stageboxes to expand the limit of 16 flex mix and 2 main mix outputs. It's possible to route the fixed subgroups to external stageboxes as well as all input channels (including Aux In etc.) and duplicates of the 16 flex mixes, which can be aux, matrix or subgroup. Nevertheless, the number of inputs can not be extended. The mixer will always be a 32 channel mixer.