I am not sure I understand your reasoning. The 4" 1911 is much thinner than the G30 and will hide very well under a dress shirt. Have you tried a tuckable holster?
I use the Galco Skyops for the 4 ¼” 1911 and the gun DISAPPEARS. It’s an excellent option for a dressier carry. Make sure you get the additional Y hook if you are going to wear it with an 1 ½” belt.
Seriously, this is a black hole of a holster.