[Enhancement] Modify how mutliple row factors appear in the output

[makostadima]

@agouy With version 0.3.8, when there are multiple factors in the rows, they appear separately as shown below:

Instead, with version 1.0.4 the multiple factors are concatenated into a very long one as shown below:

Is there any way we can go back to the previous behaviour? Or is there a setting I am not aware of for that?