Update:
Having looked deeper into the data map created with the application, 'fgszgaexoi0_' is one of the structure names created by MATLAB to store variables both as data from the workspace but also those used in the Simulink blocks.
Having further reduced my data files, I managed to get to a point where Simulink would display the application and memory allocations, showing that variables created and linked with the application are stored in RAM not the application memory - hence the cause of this issue was simply too large a use of variables, changing data types and reducing lookup tables has resolved this.