I can verify your results in both v2015 and v2019. Doesn't matter what I set the recording format options to. Also, if I say yes in the Content screen to it's offer to change the project to fit the disc, nothing appears to happen. Not sure what it could do when the settings are SLP and minimium bitrate.
If I set SmartStart to disabled, it looks like it won't import any of the files. Not sure if I needed to wait longer. I only let it go a few minutes.
If I accept the offer to merge the titles, it then creates a title which is 9 hours 55 minutes. On a whim, I decided to see what happens if I burn this project ( also added a couple of chapter markers and used titles and chapters menus. The duration of the project was shown as previously mentioned in the burn screen. I started that yesterday afternoon. Around 8 PM it said it still had 11 hours to go so I aborted the process.
I went out to have a beer and cigar. After that, I sat down to read the newspaper while still thinking about this. I decided to try it in v9. When I did (with SLP selected), it imported the files in their entirety but still warned and showed that the project was too large for the disc. The project was shown as roughly 11.2 hours. I decided to burn it and in the burn screen it gave the standard warning about possibly having a problem after burning. It burned the project in about 90 minutes.
During playback in Nero MediaHome, all the files are shown to be the correct duration.
What's interesting is that the size of the large files are shown as 621 MiB in MediaInfo so more compression was done in this process.
I decided to try importing them into other versions. v10 was the same as v9. For some reason, v11 and v12 both tell me my project is too large and I need to do something to slim it down so the files won't import enmasse. I'll work on that some more.