ok, time for some advanced corona stuff:
1) Determine the plugin configuration directory. It is somewhere in C:/Users/[your username], and it is named "Corona". New daily will be able to open it directly -
https://i.imgur.com/VfBhCMC.png2a) localize the newest Config-[number].conf file in there by date modified, or
2b) close 3dsmax, delete everything in the folder, and start 3dsmax again - only single config file will be created.
3) append new line:
bool vfb.autosave.enable = true - syntax is the same as string options. Basically the file is one big list of string options loaded when settings are reset.
4)
feel free to modify any other line (core defaults are listed in the file). You can for example enable/disable renderstamp, change renderstamp text, change image filter, material editor quality, number of threads used, clear VFB between renders, background source (corona vs. 3dsmax environment dialog), set default tonemapping parameters, ...5) save the file
New file will be created if a new Corona build adds a parameter, and at that point you will have to modify it again. But for example for 1.3 only single file will be ever created.