A small bug report... which is not even a bug... but a different side-effect than in vanilla.
When using GIF transparency (on an index different than 0), OXC can still somehow render it transparent, even though it isn't explicitly coded that way.
In OXCE, the "script blit" cannot do that anymore... so mods, which use this "side effect" don't work in OXCE, even though they somehow work in OXC.
The recommendation of course, is to use proper images... but, could you have a look if it would be easy to change the "script blit" to behave the same way?
Attached is a minimod to test it and two screenshots with more explanation.