Hello!
Let me first begin with a word of caution, flashing your device with custom firmware always comes at a risk of bricking your device and may void you of you warranty. It will also wipe your printer completely. So only do this if you do not care about any of that.
Nonetheless, while I was waiting for filament to arrive I decided to tinker a bit on the software of my Sovol 06 Plus ACE printer. I hastily (read subject to bugs) put together some scripts that allows you to change the splash screen of your SV06 ACE printer. It’s quite dirty and relies on locating and replacing the splash image in the official update image. Not sure if there is a more official way of doing this? If you are interested, any way, you can find the files on my github repository: GitHub - andrelofgren/sv06_ace_custom_splash: Upload a custom splash screen to your sv06 (p)ace printer
Note that this method requires reflashing your firmware, but should be extendable to work also on a live image. I just did not dare to go down that route.
Let me know if you find this useful, or have any comments in general.
Happy printing!
EDIT: I realized that it is possible to only flash boot.img which will keep rootfs.img intact and hence not wipe the printer. I updated my scripts on github to reflect this.