I_C_T versus I_C_T2, Questions, questions... Options

[Moongaze]

I'm going to try interjection coding sooner or later, and I have a question regarding that.
When I first tried to in my Wikaede mod, I found that simply interjecting using INTERJECT_COPY_TRANS works fine in some cases, but in other cases (such as Lieutenant Aegisfield upon first meeting) it messes up the dialogue and the actions that follow, (in this case, it prevented the Tanner Murder quest from starting). In some cases I found a workaround, by adding an extra line where the NPC in question says something back, and then it sometimes works. This, however, doesn't always work, and is an annoying way of getting by.

I've seen multiple NPC mods use INTERJECT_COPY_TRANS2 (or was it INTERJECT_COPY_TRANS_2 ?) ... what is the difference between the two, and would it be best to use the "2" version in a problem mentioned above? If not, what is recommended to ensure that the dialogues work, save not placing any interjections there at all?