concatenating single-output models obtained with MOESP subspace algorithm to a bigger model with System Identification Toolbox

Hi, I have the following problem: I have a SIMO system and I want to apply subspace identification algorithm (MOESP in the specific case). Due to the large amount of data and outputs is not possible to feed the algorithm with all the data at once but something more gradually is more suitable.

Consider I have just 2 outputs with one single input: I would like to perform subspace identification of the 2 input/output pairs independently and then concatenate them to obtain the final and complete model: is this possible with the default system identification toolbox of Matlab? Do you have any reference?