Hi,
@MrWalkman just a feedback here for the ZX300 Walkman One firmware. The external tuning folder contains tunings for Bright, Neutral/Warm, and WM1Z only. So, a total of three external tuning files instead of four as mentioned. I tried installing the Neutral/Warm one. The installer ran smoothly on my PC but after checking the device's Unit Information on the Settings menu, the line "External tuning not applied!" was there. I did a stock revert using the Walkman One version, repeated the process but still with the same result. I did another stock revert, then installed Walkman One, then tried the Bright external tuning. It won't proceed and says I need to connect the device through USB even if the device is already in mass storage mode.
These are just my observations on the latest CFW for the ZX300 which is the Walkman One. I still haven't figured out how to properly install it.