I’m trying to figure out the difference (if any) between
Is 1) even possible?
Yes.
All track recorders are available all the time regardless of what machines you have loaded onto audio tracks.
Flex machines do not record. Static machines do not record. Thru machines do not record. They play back or pass through audio, that is all.
Track recorders record audio. You have 8 of them, available all the time, to sample any source.
Octatrack is a 24 track machine. In 3 layers.
8 track recorders
8 audio tracks
8 midi tracks
Each layer is its own seperate thing.
Recording and playback are stereo, so it’s technically 40-track.
Not really. If Octatrack were a tape machine and console, the track recorders are the tape and the record head, and the flex/static are the playback head and the console channel strip. If you had a recorder with 8 stereo tracks going into a mixer with 8 stereo channels, you wouldn’t count that twice and call it a 32 track setup.
You could maybe consider it 16 track because they’re stereo tracks. But that doesn’t really make sense either since you can’t record arm the two sides of the stereo track independently, overdub onto them separately, or mix and process the two channels independently.
It’s 8 stereo audio tracks and an 8 track midi sequencer.
We’ll have to agree to disagree.
Enjoy your Quadragintitrack! Yes I had to look up the prefix for 40. 
Yeah, let’s add more irrelevant and confusing information and also say that one could argue that polyphony involves note channels, therefore each MIDI track has 4 channels of polyphony, so we are looking at 64 channels total, cool!
Anyway, to add to @Microtribe’s explanation, the only difference is that a recorder buffer is being used and played back from an audio track that has different configurations. If it helps, you can record into a buffer from a track 1 and access that same buffer from track 1, 2, and 3 if you wanted to. Each track could be set at chef’s choice, but the underlying buffer is the same.
The 8 recorders being accessed via the 8 track buttons naturally leads people to thinking tracks and recorders at linked, but they aren’t. It’s a UX decision we have to live with and 13 years on seems churlish to complain about now.
I do wonder how many people have utilized all 8 recorders simultaneously, it’s a wonderful bit of overengineering, bordering on the hilarious
They kind of are though. You have 8 tracks of recording which are linked to the 8 buttons. Then you have 8 mixer channels which are also linked to those 8 buttons. But you have the equivalent of a patchbay in between so you can take the recording from one track and route it to the mixer channel of any other tracks you want.