Close. A few comments...
Creating and Saving 16-bit Files1. You have this step correct. FWIW, Audition doesn't actually convert a 24-bit file to 32bfp on opening. It's still 24-bit data, but within a 32bfp "workspace". You can confirm this by opening a 24-bit file, then running
Analyze | Statistics from the main menu before you make any edits: the bit depth should read 24-bit in the statistics.
2. Again correct. It's during these edits that Audition "converts" to 32bfp. Any section you edit will be 32bfp after applying the edit, since Audition uses an internal bit-depth of 32bfp during processing. If there are sections of the WAV you have -not- edited, these will remain 24-bit.
3.
Convert Sample Type first, to resample to 44.1 kHz before dithering. Set the bit-depth to 32bfp (which will disable the dithering checkbox and options).
4. Apply MBIT+ to dither down to 16-bit. If you run
Analyze | Statistics after dithering, you should find the bit depth shows as 16-bit.
5.
Convert Sample Type again, setting the sample rate to 44.1 kHz (it won't actually resample since this sample rate matches the rate of the data, now, due to step 3.) and the bit-depth to 16-bit (with
Enable Ditheringither UNticked, since we already dithered in step 4.). All you're really doing here is truncating the bits below 16-bit (which are simply padded with 0s, after dithering), since for some reason Audition won't let you save directly as a 16-bit file without doing so, first.
6.
Save AsCreating and Saving 24-bit FilesIf you want to save as 24-bit, the workflow is slightly different:
Steps 1 and 2 are same as above.
3. You probably won't resample if you're saving as 24-bit. But if you do, this step's the same as above:
Convert Sample Type first, to resample to your preferred sample rate before dithering. Set the bit-depth to 32bfp (which will disable the dithering checkbox and options).
4. Apply MBIT+ to dither down to 24-bit.
5.
Save As. In the
Save As window press the
Options button, then in the
Windows PCM window,
Format 32-bit data as dropdown, select
24-bit packed int (type 1, 24-bit) and UNtick the
Enable Dithering checkbox (since you've already dithered from 32bfp to 24-bit in step 4.).
Creating and Saving 24-bit and 16-bit FilesIf you want to create both 24- and 16-bit files, save the file in 32bfp after step 2. Open it and perform steps 3-6, from the 16-bit section above, to save as 16-bit. When done, re-open the 32bfp file, and then perform steps 3-5, from the 24-bit section above, to save as 24-bit.
There's a bit of discussion
here, from a while back when I went through the same learning curve.
To answer your specific questions: it's okay to dither straight from 32bfp to 16-bit (or from 32bfp to 24-bit, if you want to save 24-bit files, too.)