TL;DR - do not install my releases to any device with assigned drive letter A:\ or B:\. Entire english alphabet works but not these first two.
Some easy example first based on 5MB file "Foundation update 1.11.0.7 - 1.11.0.11.exe"
C:\Games\Foundation - All OK (default installation path suggested by installer)
A:\Games\Foundation - update gets stuck forever
B:\Games\Foundation - update gets stuck forever
Drive letters A: and B: are reserved for floppy disks, they have also +30Y old floppy disk bug/feature. Simply avoid installing my updates to partitions A or B. Around 300-500 of my ISO releases will also hang on these two letters when installation will reach 100% progress.
I must say I didn't realize anybody is using them. Apparently current young generation for some reason likes to create disk partitions under letter A: or B:
This bug will be eliminated and all future installers will work in A\B drives as well. Changing drive letter takes 15-60 seconds, tutorial here. Info will stay on top for about 30 days.
Some bonus info
Recently I made a test on brand new Windows 11 25H2 with all possible security settings enabled. Secure Boot ON, Memory Integrity ON, Kernel Stack Protection ON, Windows Defender ON (+SmartScreen +AntiMalware), Controlled Folder Access ON, UAC ON, Bloatware/Crapware ON - all defaults by Microsoft + all Windows Updates. Under these conditions Foundation game ISO and 5MB update work without issues (in default path "C:\Games\Foundation"). I am leaving this as a note to those who say there's a difference with/without antivirus (of course AV other than WinDefender may behave differently).
And the last one, some info about patching on a crappy PC with cheap NVMe/SSD. Imagine you have 250GB NVMe/SSD, after formatting 230GB, after Windows +apps installation let's say 200GB left. Later you install ONE 100GB game to this drive, so 100GB left. This 100GB game has few dll files + 150MB .exe + ONE SINGLE 99GB PAK/UCAS file. When you try to patch this game, in the very last moment of updating process, there will only 1GB left of free disk space. If you try to do that on a cheap NVMe/SSD speed may decrease to as low as 1-10MB/s, so it may take hours to complete. I know, rare, extreme scenario.
To estimate how long patching process should last, select entire game folder and press CTRL C + CTRL V. Copying in-place of 150GB Stalker 2 folder took 120 seconds? Patching will also need the same + usually 5% extra.