[ACGAuthor]

Yikes. That makes my issue with the disappearing display in the car seem pretty easy to navigate in comparison.

The deeper I get into it, the more it looks like the way to accurate series management may be to handle them as podcasts instead of audiobooks.

When I made the audiobooks Podcasts in the options tab of iTunes instead of Audiobooks, all the metadata I needed to make them fall in proper order and play the way they should was right there, assuming I set the release date metadata so that they were released in chronological order. There were a couple issues that I was able to navigate around, however.

Issue 1 - editing the release date isn't possible in iTunes. Okay. I opened the file in Subler and edited it there. Once I reloaded it into iTunes, it was perfect.
CLARIFICATION: Upon further exploration, I realized, while editing the release date doesn't seem to be possible once you're in the podcasts tab of iTunes, you can edit the release it while it's still an audiobook and then change it to a podcast in the options tab.

Issue 2 - Podcast app on the phone doesn't seem to recognize chapters when the "podcast" files are .m4b. Once I changed the extension to .m4a, it recognized the chapters just fine.
CLARIFICATION: This appears to be a Apple Podcasts-only issue. Downcast has no problem with the files being .m4b and handles the chapters just fine.

The remaining issues are nitpicky stuff that can't be fixed without finding a new podcast app for the device. The Podcasts app on the device will only display the cover art for the first "episode," and it doesn't have buttons to navigate forward and backward between chapters.

So I need to find a podcast app that allows sideloading, displays episode-specific artwork, and has buttons not just to skip forward/backward a certain amount of time but between chapter markers. It looks like Overcast may be what I need, but only if I'm willing to pay the $10 a year. Downcast, at $3 one-time, may also work, but I can't figure out if it actually allows sideloading or not.

This could fall apart when dealing with series where the audiobooks were not released in chronological order, requiring one to falsify the release-date metadata, but I think my OCD tendencies will allow me to get away with that if necessary.

ETA: Based on preliminary testing with the Beta version through Testflight, Downcast is the bomb and will handle series exactly the way I'd prefer it be handled. Sideloading options are a little limited and may require some workaround creativity, but it works. I was able to Airdrop files from my MacBook to my device. They went directly to Evermusic's directory structure, however. But I was able to browse to Evermusic's media in Downcast and import it into Downcast. Chapters were marked in the timeline of the file, Prev/Next buttons moved between them cleanly, "episode"-specific cover art was displayed perfectly.

I think I may have cracked this thing.

Downcast works really great with Apple CarPlay. Unfortunately, the ability to navigate between chapters goes away there, however. The prev/next buttons on the dash do nothing, and all that's displayed on the display are the time-skip forward/back buttons. You could still use the phone to skip between chapters if necessary, however.

Downcast is definitely not hugely intuitive as far as how to sideload, it's really quite clunky, but if you upload your files to iCloud you can do it, or if you transfer them via AirPlay to another app that allows it, you can probably find them and load them into Downcast.

For the $10 a year pricetag, Overcast might be a better option, except I'm concerned because (unless disabled) it looks like the prev/next buttons on the steering wheel will take me to the last/next file, rather than through chapters, and that's exactly what I DON'T want. The reason I'm so determined that I need CHAPTERED audiobooks is because I keep hitting those darn things by accident and losing my place in unchaptered audiobooks. I may email Overcast support and ask if they can be set to navigate between chapters, and if so, I may drop the $10 and see if it works better than Downcast.

But yeah. Apparently the key to effective series management is to make them podcasts. I'm gonna continue to play around and see if Downcast will play nice with Audiobooks that aren't "podcasts". Once I've got it all worked out, I may do little guide.