Parameters use_gapfilling and data_mode_access

From the the documentation it is not clear how are related the following parameters:

• use_gapfilling: it enables or disables the use of gapfilling for the time series, e.g. to have the same set of temporal feature for different tiles.
• data_mode_access: it allows to choose which data can be accessed in custom features: the original data or the gapfilled data or both of them.

It is not clear to me if the second parameter overrides or not the first one: For instance, if I forgot to set use_gapfilling=False but then I asked for raw data in the external feature with data_mode_access=raw, what's happening ?

From #427 I have understood that if concat_mode=True we get an error with several tiles since we get samples of different size.

So I conclude these parameters are independent in the config file but may mess up according to other parameters: I have identified the parameters concat_mode and maybe fill_missing_dates (yet I don't know how).

Is my understanding correct?