"New Hotness"
All of the individual Buffers that LightWave uses to calculate its final render are available to both pixel and Image Filter Plug-Ins, so some clever programmers began coding tools that would sift through these Buffers and save-out each Buffer you chose, either as each Antialiasing pass (pixel Filter) is rendered, or after the whole image is rendered, and ready to be saved to disc, (Image Filter).

Some of these Buffer-Saving Filters worked better than others, but all of them let you "Break-Out" an Image into its various component parts, (Specularity, Reflections, Shading, etc.,) in one, render pass, and with a minimal amount of drudgery.

File Format
Not all high-bit-depth file formats are created equal. Some can't hold Alpha channels... some have slight "noise" through areas that should be a constant value... some are limited to 16-bits-per-channel, some are Integer, some are Floating Point, some can be either... and some allow for the saving of more than just the standard, Red, Green, Blue, Alpha channels within a single file.

Early on, I explored LightWave's Photoshop PSD Export filter. It comes with LightWave, gives you a wide range of Buffers and controls, embedding the channels all into one, easy to manage file, and gives you the ability to save 16-bits per channel images. The two caveats I found with this is that the files can get to be pretty sizable, and a lot of Photoshop's tools were disabled when you worked with a high-bit-depth image. (You could still work in Cinepaint of Fusion with this kind of high-bit-depth image, but if you wanted to use GIMP or Photoshop to natively explore the 16-bit option for these files, your options were limited.)