hi,
if you read the description in the original thread you’ll realize you need a movable skylight. so no, this local IBL system is not the right thing for your setup.
the entire system relies on the UE4 limitation that the movable skylight works as a general ambient light that acts everywhere in a very homogenous way, and my system uses the reflection probe data to ‘blend out’ the skylight and replace it with the reflection colors acting as IBL.
the system is aimed to improve upon the limitations of fully dynamic (movable) setups.
in your case since you’re already using a static setup for the stationary skylight I suggest you bake everything that you need as static/stationary and put movable lights on top for any dynamic effects.
if the amount of lights in your rooms is small (you mentioned 1) you can use stationary lights so you can get good baked GI and also be able to switch them off at runtime.
a static/stationary skylight coupled with a dynamic directional light can produce visually good results. you get a bit of the worst of both worlds (you need lightmap UVs, wait on light build times, and the performance cost of dynamic shadows on the directional light) but a bit of benefit from both worlds ( since your skylight gets baked you get good baked AO, and you can still rotate/color the directional light, and tint the skylight if it’s stationary)
this is the result of such a setup that I made some time ago. a stationary baked skylight + a movable directional light
https://i.imgur.com/LSTIuBj.gif