Scanner software and LR donít let you do real RAW processing, but you can get close. The less you do to your scannerís CCD output, the closer to RAW. For example, if you output aRGB, that is a step away from your scannerís native color space and a step away from RAW. (Iím not saying that there is anything wrong with outputting aRGB, itís just an example of a difference from RAW.)
Just to be clear, so long as your output color space isnít smaller than your scannerís native color space, it probably
makes no difference in LR whether you work with aRGB output from your scanner or the 16 bit linear output from your scannerís CCD (as long as you properly color manage that linear output). My scannerís color space is larger than aRGB, so I use ProPhoto. Itís likely that your Epsonís native color space is also larger then aRGB, but I donít know if that difference would be significant.
With my scanner, I can take the same 16 bit linear file and make two versions of it. With one I assign my scannerís linear profile, but otherwise leave the file untouched. Itís still in linear, which can be seen clearly from the histogram, even though the photo now looks normal. For the other version, I go one step further in that I convert to ProPhoto. In other words, I first assign my scannerís linear profile and then convert to ProPhoto. Now, the photo not only looks normal, so does the histogram. If I then process both versions in LR, using all the same settings, the results are identical.
I havenít done such a test using aRGB, so itís possible that using aRGB could make a difference (over and above just a gamut difference between my scannerís native color space and aRGB).