Thank you Kulyok.
Yesterday I installed Xan Friendship V9 on BGT without error. I played a bit until I got the first talk. By mistake, I installed the mod in Italian. This allowed me notice that the italian tra file was actually encoded in UTF8 instead of CP1252, so that there are bad characters in the text displayed anytime a special character should be displayed.
I compared the three archives, v8 Windows, v8 Mac and v9 Windows. They all include the same tra files. So the italian file is in UTF8 in all of them and has to be replaced by the CP1252 version in all of them.
The fact the italian tra file is already in UTF8 is also an issue for the BGEE version, as converting the file from CP1252 to UTF8 when the initial file is already in UTF8 will generate some garbage characters in the resulting file.
Moreover, the tp2 file is identical between v8 Windows and v8 Mac. Basically the only difference between the two versions is the readme file and _xan.baf/xan.baf files, where a timer is set with different values. So Windows and Mac versions are identical, except for the weidu binary and the command file for Mac, and the readme content, which you could probably unify by adding section for Mac and Windows in a single file.
Comparing v8 Windows and v9 Windows also show the only difference is the tp2 file (and the readme), plus the fact that v8 is using NSIS (I compared after NSIS extraction). In the tp2 file, the main difference is the ALWAYS block, which will be enabled only on BGEE (it won't interfere with others), and the fact that BGEE specific parts are within comments in v8.
I'm fairly certain that changing the tests to determine the base game from checking file presence to using internal WeiDU GAME_IS capability is not going to break anything. In my opinion (and the successful installation of v9 on BGT confirms it), you would be able to establish v9 as the unique version for BG, BG1Tutu, BGT and BGEE.
You can find the italian tra file converted to CP1252 in this archive
I noticed a mistake in the conv_tra.sh file I gave you: it's using Windows end of line instead of Mac OS X/Linux one. It will probably not work on Mac OS X as is. I put a fixed version in the archive.
I also suggest you remove the bgee_install_xanbg1friend_setup.bat file from the v9 archive together with weidu.exe. The bat file is enforcing the use of the english language in the game. Now that WeiDU 232 and beyond is available, the player can select the BGEE language when installing the first mod, so there is not need of a bat file to tell the game language to add the texts to.
To sum up:
- replace the italian tra file in all versions of the mod
- replace the conv_tra.sh file in the BGEE archive
- remove bgee_install_xanbg1friend_setup.bat and weidu.exe in the BGEE archive
- you could keep a single unified Windows version based on the v9 archive with these changes
After reading the guide posted on G3, the Mac version seems to met all conditions in the TP2.
I expect the adjustement for BGEE should be compatible (given you replace the conv_tra.sh file as mentioned above).
Regarding a Mac version for BGEE, my understanding is it's no use providing WeiDU in the archive as the player has to download a version suitable for its Mac OS X version (contrary to Windows, there can't be a single executable). For reference, you can find instructions to install mods on Mac OS X for BGEE in the following thread