I've managed to play through 3 of the 4 scenarios to check Longer Road/Turnabout compatibility (Accepting a new soul through Ilmater remains elusive), and I have repeated the finale a good dozen times with variations on these endings and Turnabout's options. Unfortunately, I noticed after my playing that the version of Longer Road I downloaded through the Studios mirror is marked v1.5, whereas the forum has an offsite link to v1.5.1. Hopefully, the differences between the two versions do not render my efforts null and void.
Some of the problems and gaps I saw during testing that players may notice:
- Khalid, Dynaheir, Tiax, and Yoshimo will not react to Irenicus being in the party if they are revived via a pool.
- LR assigns Alianna (the PC's mother) a portrait for her appearance before the second challenge. Alianna will have a different portrait when revived via a pool. (Turnabout varies them depending on the PC's race.)
- There are no reactions from Turnabout revived characters when Irenicus takes the PC's soul.
- For the ending where Irenicus takes the PC's soul, only Turnabout and LR epilogues played before the end credits. Bioware epilogues were skipped.
- For the endings where Irenicus takes another Bhaalspawn's soul or is sent back to the Abyss, Bioware and LR epilogues played before the end credits. Turnabout epilogues were skipped.
In summary, players should not have any problems completing ToB, and they will not miss any Longer Road material because of conflicts between these two mods. They may, however, notice the lack of cross-mod content or missing epilogues.