Modular level design is essential for mobile VR due to how culling of surfaces is done on mobile GPUs. However, ISMCs and HISMCs perform poorly on Gear VR (referencing Gear VR here because that’s the platform I’ve been working on and testing intensively). Not only they perform poorly, but also distance culling per instance doesn’t work. Distance culling works only for the entire (H)ISM Component, which makes it useless.
Imagine dungeon built of modular (H)ISMCs and player being in the middle of it. All instances beyond whatever distance culling value was set should not render and whatever instances are visible should perform at least at the same level as if it was built with individual actors. Currently level built with (H)ISMCs performs worse than the one built manually having all pieces as individual actors.