I’ve had the same problem with loading a scene which uses live camera (AR with Kudan). In the split APK that scene loads about 20 times slower. I tried revision 5.4.3p but that made no difference. For now, I have patched it by making the AR scene load first-- I inserted a black screen that loads the menu scene OnEnable tied to a static variable bool, so that it only does it the first time (previously the menu scene had loaded first). This almost doubled the size of my APK (and correspondingly reduced the size of my OBB), and has fixed the problem. I now notice no slow loads… but definitely a work-around!