Been testing with 5-6 different types of USB-C and TB3/TB4 cables from my shelf today, and in a classic apple move, the OEM Silicone Case for iPhone 15 Pro's USB cutout area is JUST narrow enough that the only cables that fit, in my testing, are the following:
-apple OEM USB-C cables, meaning the white ones and the black pro cable/TB3/TB4 cables
-One caldigit TB3 cable where the plastic behind the metal connector was the same shape as the opening on the case, but another TB3 cable by caldigit but newer generation did not fit because it was squared off
Any conventional USB-C cable that has a squared off plastic surround behind the metal USB connector will not fit, you'll have to remove the silicone case each time.
Tinfoil hat on: they did this on purpose to sell more OEM cables.
-apple OEM USB-C cables, meaning the white ones and the black pro cable/TB3/TB4 cables
-One caldigit TB3 cable where the plastic behind the metal connector was the same shape as the opening on the case, but another TB3 cable by caldigit but newer generation did not fit because it was squared off
Any conventional USB-C cable that has a squared off plastic surround behind the metal USB connector will not fit, you'll have to remove the silicone case each time.
Tinfoil hat on: they did this on purpose to sell more OEM cables.