If you rename the file to whatever target layer you want - it will create that layer automatically for you on import. So if you have say Rev 1 cross sections and then Rev 2 cross sections, provided that you have Rev 1 and Rev 2 in the file names they will create the layers for you automatically and keep the data separate - this is as quick as Using Layer Manager to create the layer during the import process (if not quicker), and also helps you to manage the File Names of the Imported files. Same for if you have section files in XSR or GEN formats then if you have files for OG and files for Design it will separate those onto different layers also.
We figured that the File Name should tell the software what it is getting - agree that you may then need to add those Layers into Groups or rename after import if you dont like what you called the files etc.
Alan