I understand that the size of your Simulink project keeps on increasing despite of no changes in the structure or data usage.
When you save a Simulink model with two or more Simulink Editor windows open, information is stored in the model file to recreate those windows when the model is later reopened. However, in some circumstances, that information might increase in size with each save cycle. Eventually, this extra information can slow down the process of reopening and resaving the project.
A workaround for this could be to close all but one Simulink Editor window before saving the model. This mitigates additional file size increases due to extra window information, but it may not reduce the number of copies already created.
You can refer to this MATLAB answer for more clarity - Simulink file size keeps on increasing! - (mathworks.com)
