Looks like the error message "The following component(s) are required to run this program: Microsoft Visual C++ Runtime" is related to SteamRT3.
After disabling SteamRT3, the game is able to install the required components.
Given the steamrt3c link, my first guess would be that the experimental steamrt3c Steam Client might be running Proton games' setup commands (such as installing the Visual C++ Runtime) inside the steamrt3c container, instead of in a parallel container, similar to https://github.com/ValveSoftware/steam-for-linux/issues/13006.
If yes, that would be a Steam Client issue more than a Proton issue.
Compatibility Report
System Information
I confirm:
steam-2624870.log
Symptoms
After launching the game, an error window appears with the following message:
"The following component(s) are required to run this program: Microsoft Visual C++ Runtime"
Reproduction
Always.