Slow playback resume load times for large Audible files - v1.29

After flashing v1.29 to get Audible to recognize my new Clip Sport, I downloaded a single audiobook file that is aproximatel 48 hours long and 1.3 GB in size.  My old Clip Plus handled these large Audible files with no problems, but the battery failed after 2 years of heavy use.

Imagine my dismay to discover that the replacement Clip Sport I just received apparently requires a playback resume load time that increases as the file postion advances.  For example,  hitting the play button to resume playback at the 30 hour mark takes over 5 minutes before the playback actually begins to advance.  At the 40 hour mark, the playback never resumes, the Clip Sport freezes and requires a reset.  

Whaaaat?  Sandisk discontinued the Clip Plus for this?  Really?

Is there anything helpful in the discussion at this weblink?  Maybe the problem you describe here is not restricted to the SanDisk Clip Sport?

        “All Audible books longer than a certain time, something like 24 hours in Enhanced format will have this problem. Apple and audible are aware of the problem and Apple seems to have no real interest in fixing it. Audible suggests that one set the Audible library page to split the book up into sections”

This issue has been discussed previously. It’s an issue unique to the Enhanced mode. The further into the file you get, the longer and longer the resume function takes to start up. There’s also reports that the final 2 - 3 minutes of the every audiobook are dropped compeltely.

The only workaround is to drop back to Mode 4 which offer smaller file sizes and multiple audiobook parts. There’s no issue with Mode 4 playback, except that the Sport doesn’t handle the multiple parts well as it appears to cut off the file name after a certain length. If the Part designation (1 vs 2 vs 3, etc) s after the cutoff, the parts may not be ordered correctly. You’ll need to know the exact length of each part to know you’re in the right order.

What Audible needs to do is create a Mode 5 that has the file size and quality of Mode $, but comes as a single file.