I decided to register and share my observations, hello everybody.
So we have crash, place - Chares View Amphitheater, Emogene Takes a Lover quest.
Tried some crazy things like going there naked, w\o sound, in full screen with low graphics and so on....crash crash crash.
Then I started to look at my early saves, I save game a lot. Unfortunately, the closest is not broken is almost 5 hours ago, not so bad considering 3d11h total(Yes I play F4 almost 24\7 ).
So we have
3d6h37m save - crash
3d5h51m save - mo crash
As you can see it's a very little gap, less than hour, more importantly - this hour is just after i finished BoS introduction, I took Learnng Curve(Corvega Assembly Plant) and second Quatermastery(Greater Mass)+Cleansing(Four Leaf Fishpacking) side quests. Somewhere in the next 2 hours I found Cabot House and this entire storyline with Emogene and Amphitheater. So last time I did BoS side quests and despite those quests pretty far they still somehow broke my savegame, and it is happend in 50minutes time frame.
All in all in this 50 minutes I visited Country Crossing, Greater Mass Blood Clinic, Four Leaf Fishpacking Plant, Nordhagen Beach, Cabot House, Parsons State Insane Asylum, place with racing robots, forget it's name and maybe few more, still it's only 50 minutes. Now I will try to do every quest I did first time but I will go to Chares View Amphitheater after every quest update to check, maybe I can catch this f....piece of codfe that broke my save.
For now maybe my observations will help someone. I'll write later after I do all(that I remembered) quests from the first try.