My understanding about the Tascam DP24 brings two considerations to the discusson here:
1) If you examine a card formatted and used in the DP24, there is a Music folder with a folder or two for "system management" and then a folder for each song you have on the card. When you open the folder for a particular song, you find in some cases many, many tracks, each containing a snippet of the song. Off hand, I do not know of a file which would give you separate access to each track of the 24 total which you use in your song. My point here is that I'm not sure how much good you can do if you try to use the files in a "song folder" to apply for mixing in another production system. I welcome any information anyone has on this point about the file structure of the Tascam DP24. (for operation without sight, I have been letting the dP24 "name" each song I create; thus the file names of my songs are of the general format "SONG.abcd" where "abcd" are digits. So far, my songs have been something like format "SONG.0028". I use that approach because I found it very difficult for me to do all that scrolling to select a literal song name.)
2) If you export a song to the DP24's Audio Depot, you get a standard stereo copy; again, there might be a way of which I am unaware by which one could export all the separate tracks to the Audio Depot.
It appears to me that one consequence of the DP24's system is that, while you can record the tracks of your song, bounce tracks around to free up tracks for reuse, mix everything down to a two-track stereo copy, and master the mix using the DP24's Mastering facility, there is not a way to get a folder with, for example, the separate 24 tracks of a multitrack performance so that they could be taken somewhere and mixed and mastered on more sophisticated equipment.
But for me in my recording endeavor, that setup is fine for me. Until I learn more about using the mastering facility, I'll use the Focus Scarlet II interface to get from the DP24 to my computer in the final form of any song. I just "do the mix" by adjusting all the used track faders for the mix I want, then play out the recording from the DP24 to Audacity via the Focus Scarlet II. I still plan to set up a "lab song" on which I can play with the Mixing and Mastering functions of the DP24. The main point I have learned about the Mixing section is that one must first Mark the beginning and end of the portion of the recording which is to participate in the mix. That's how one can allow some extra sounds to give a chord for tuning or cue the starting of a song. That also allows one to eliminate any extra sound which happens after the music is finished - as might happen if one has to walk away from a keyboard to move to the recorder.
The Mixing process creates a special file on the Dp24, and that file is dedicated to the Mastering operation. If the marks are placed precisely and the performer(s) are careful to keep the second or so on each side of the song clean, the final product should be free from any extra unwanted noises at either end of the song.
I know, of course, that I don't have a "professional" setup, and I doubt that I could afford one or even be able to operate much of the professional stuff these days because so much of it is heavily "mouse/touch-screen dependent" and "visually rich (often 'accessibly poor' for a totally-blind operator)." Still, I have a "hell of a good time" making music with the equipment I have.