How to profile entire game performance (Ludeon, provide symbols please)?

[HelloKitty]

Greetings.
I have 100 mods and my ticks per second are low (like 100-200 max, but sometimes under 60 + stuttering) when I have 25 pawns and 100 animals. I'd like to troubleshoot this. My main assumption is that the main culprit are mods, because I have an extra top PC for $8k, specifically picked for single threaded games.
So I used to make private modpacks in Minecraft and Factorio. With java it is easy: jdk is great - I can use jconsole with plugins, jvisualvm, java flight recording & more. I always see how much CPU do which threads / actions consume, I always see the detailed human-readable stack traces.
With Factorio it is harder. I tried "Very Sleepy CS" program, and it somewhat does show what I'm looking for, however I have a hard time interpreting it for now. The most important part here is probably that stack traces are human-readable.
When I try Very Sleepy CS with Rimworld, I only get system functions and memory addresses, that's it. I understand it that Rimworld was compiled without "symbols". How do I get those?
Additionally, I installed unity editor and tried to attach Rimworld to it, but alas it doesn't work that way (duh?). Unity editor has a nice profiler with guides on youtube.
Finally, I see some people recommended a "custom mono.dll with a built-in default/basic mono profiler". What is that, where do I get that, and how do I use it, are there any manual anywhere? Is this even valid for my purpose?
Thanks for any advice.