Any of those red loot boxes that Sykes opens up for you left in Residential and City Hall area?

[Berghain]

I'm asking cause I really can't remember, and if there weren't any in those 2 locations, then there's really no need to backtrack for now.

[Greed Is Addiction]

Only 3 I found in the game - all had ammo components. I scoured for them. After a certain point in the marrow, you can't go back.

[Berghain]

A-ha! I've also got 3 so far. So I guess that will be it, then. One less thing to worry about :)
Thank you!

[Harukage]

I only saw 4:
1. server room
2. sykes safehouse
3. warehouse where you can get fullbarreled shotgun
4. rooftop oposite to the theatre's area entrance.
All but one in the server room are in business district.

P.S. Also note that when you get to business district the second time in the story all red boxes get new loot.

[Berghain]

Aah, I think I missed the one on the rooftop oposite to the theatre. I'll go get that one right away :)
Thanks Harukage!