So there was this mod that made sky visible in Institute HQ, but it has some bugs. I made this as an alternative.
Permissions and credits
Credits and distribution permission
Other user's assetsAll the assets in this file belong to the author, or are from free-to-use modder's resources
Upload permissionYou are not allowed to upload this file to other sites under any circumstances
Modification permissionYou must get permission from me before you are allowed to modify my files to improve it
Conversion permissionYou are not allowed to convert this file to work on other games under any circumstances
Asset use permissionYou must get permission from me before you are allowed to use any of the assets in this file
Asset use permission in mods/files that are being soldYou are not allowed to use assets from this file in any mods/files that are being sold, for money, on Steam Workshop or other platforms
Asset use permission in mods/files that earn donation pointsYou are not allowed to earn Donation Points for your mods if they use my assets
Console modding permissionThis mod will not be available on Bethesda.net for console users
Author notes
This author has not provided any additional notes regarding file permissions
File credits
This author has not credited anyone else in this file
Donation Points system
This mod is not opted-in to receive Donation Points
So there was a mod that made sky visible in Institute HQ, but it has some bugs. I replied in the comments and it seems the mod isn't active anymore, so well, I made one myself.
*This is fixed in version 1.2 The rooms above are still visible if you play on high FOV, but 99% you won't even notice them. This mod also fixes sky brightness at certain angles.
Also, unlike the original mod, this mod doesn't use Sky Lighting, so the interior won't get affected by the day/night as much, only mist and ambient lighting are.
Interior lighting at evening:
*** Note: Put it at the bottom of load order or the sky might not show up at all! ** *