Hey there,
Generally i find many problems on the internet or forum. But this problem is probably a rare one. Target platform is android.
Lighting → Other settings → Fog disabled → Build size 116 Mb
Lighting → Other settings → Fog enabled → Build size 137 Mb
21 MB just for fog? No other changes. Just enabling fog and build size increases dramatically. Searched internet and cant find any solution.
This is the nature of shader variants. Fog is implemented using a multi_compile with 3 keywords, so you effectively multiply the amount of variants by 4 (3 + 1 variant with no fog keywords) for relevant shaders. If the shader already has many variants (often the case for ubershaders), that can be a huge difference. The tradeoff is better runtime performance, at the cost of longer compile times and more variants stored on disk.
So many thanks for the answer and link. Shaders are everywhere. In this case there is nothing to do for me now.
Kind regards.