Enlighten realtime GI indirect lighting buffer size. Bug or feature?

Enlighten realtime GI have limited buffer size, how much?
I build simple scene from 100 cubes, and have issue: not all cubes is illuminated, only first 45 cubes.
I generated lighting with hightest lightmap parametres for precomputed realtime GI and turn on Final Gather, but result is same:
in Unity2018.1.3f1:



in other versions of Unity:



Unity 2017.4.5f1 has same result.
Project file Unity2018.1.3f1: https://drive.google.com/open?id=1Gi5A07VQoGCrn3i4cMDtDftFi5G880gc

Size limited in texture size, object count, clusters size, ... ?
If it not bug, then is very limited size.
If it bug, then bug is very old, since Unity 5.6

 

I found not stable solution.
I change "System Tag" in Lightmap Parameters in cubes.
Need to try change for each cube Lightmap Parameter "System Tag" by hands, until you find the correct result, I not find a specific algorithm.
Tested in Unity 2018.1.3f1 , 2017.4.5f1.
Its look like not a bug, this is feature.

 

It's feature that not always works like you want

If you're going for baked lighting and don't want the precompute stuff, you could switch to the progressive lightmapper.