Edit factory defaults with custom firmware

Questions
1

Does anyone know how to edit the firmware so that the factory defaults are different?
I’m using an ESP32 and would like to edit both the audio reactive and non-audio reactive ver of WLED with different defaults.

2

You can compile firmware yourself with different flags.

3

This might help you: https://wled-compile.github.io/

4

Thank you Jink,
I got the below when I entered LED GPIO 2output and Relay GPIO 12. That’s 2 of my goals.
The other 2 goals wanted was:

  1. Set a LED channel 2 to a GPIO 4, with LED count to 1.
  2. Activate a particular effect on boot.
    Is there anyway to edit the below code manually to do those things?
[env:custom_build]
extends = env:nodemcuv2
build_flags = ${env:nodemcuv2.build_flags} -D LEDPIN=2 -D RLYPIN=12```
5

Hello everyone,
I’m also trying to figure out how to have the audio reactive enabled by default.
any help would be apperciated!