Although SeeU currently only has a Japanese and Korean voicebank, it seems as though she may be receiving an English voicebank in the future. Recently, a fan decided to message SBS about the possibility of an English voicebank. SBS Artech replied, saying that they originally planned to make an English voicebank for SeeU. Due to a tight schedule, they weren’t able to officially release an English voicebank, but some sounds that are not present in Korean or Japanese were included so that English pronounciation would be possible to some degree. SBS is now working on a proper English voicebank, and hope to have it released this year.
Source: SBS Artech