When using a unicode character in the config.json this is scaped when compiled and in the label shows \E and not the character itself.
config.json in the global section:
When open the compiled version of CFG.js it shows like:
And using Alloy.CFG.icon.bus in the app result undesired apparence.
Changing "\ \uE530" with "\uE530" the compiled version of the file CFG.js with liveview active works as expected.