How do shadows in details affect the performance of UNITY?

Question

Unity

In short, it's clear - more shadows and lights with shadows - more DC - slower.
But is there any way to get around this? Me in what sense. Let's say I have a lot of point lights on the scene at the same time with shadows turned on. Let's say 100. It is clear that with such figures, adequate performance cannot be obtained.
But what if I have very little ShadowCaster at the same time? Well, let's say only 20. I need a lot of lights and shadows are not necessary, but somehow these sources need to be limited to rooms. Those. in one room, let the lantern shine without shadows, but does not affect the next room in any way. I want to put a ShadowCaster between the rooms and thus limit. Will I get adequate performance on Deferred rendering, or will the fact of sources that calculate shadows hit hard enough, and the number of Shadow Casters plays little role?
The graphics in the game are such that you can really see a lot of sources at the same time. It will not turn out to include only some at some point.

Answer 1

100 * 20 = 2000 Do you have 2 thousand shadows displayed, and even in real time?
If the sources and objects are not moving then here is the solution.
https://docs.unity3d.com/Manual/LightMode-Baked.html