Sorry for the delay in response, but needed to comb through the code just to confirm my thoughts... If the product_name_X (where X relates to the language) is not included in the imported file, then the description will not be updated. Also, it appears (though not tested) that if product short description is installed/verified by the code to be present, that the absence of data in that column (or column not existing) may result in the short description field being cleared. I haven't fully followed that path of the code to identify, but it is also one reason that it is suggested to backup the database before importing a file and checking the database/site after upload to verify no ill effects.

So, with the regards to "management" of the data in this update... There is no reason you couldn't move columns off to the side while maintaining the sequence and content so that you can have a clear "click" region to help with updating. Then prior to update, remove the extra space and voila any concerns of missing columns is addressed.

One of the thoughts behind this is, how easy it for the standard user to know what product is being updated if all that is present is the model #?

On to that as well, the rules of duplicate model# or missing model # also still apply. In the case of a duplicate model number, the last version of that model #'s data will override all previous data for the same model #. In the case of blank model data, I thought that the response was that the data provided with a blank model # will replace the data of the previously provided model#. If a model # is modified and that model # does not currently exist in the database, then a new product will be created/entered with the data that is provided in that row....

So there are a few things that are considered necessary in order to support updating, but remember that whatever is uploaded might need to be reviewed in the future, so how little do you want to include in the file to understand what went wrong if a problem occurs?

BTW, if it has been a while since your EP4 has been installed, there have been some features that have been added (including that it is no longer necessary to include the description field upon upload) and available in the more recent version(s). To "refresh" the configuration screen to include any newly added options, would suggest documenting the current settings of the configuration->Easy Populate 4 window, clicking the uninstall link at the top right corner of the tools->Easy Populate 4 window, uploading the new files, then selecting the install link in the center of the screen of the tools->Easy Populate 4 window, then restoring any settings that were modified/reset.