I think that, instead of Japanese CV, beginners should try Japanese CVVC as their first voicebank. While CV is super simple to record and oto, CVVC teaches concepts and skills similar to VCV, VCCV and arpasing. I'm not against CV voicebanks. In fact, I used to have zero interest in non-CV/VCV voicebanks until Xia Yu Yao came along. I just think CVVC is very useful for learning how to oto.
Edit: I cut down the length because I got too wordy...
There is also a tutorial for removing vocals, but be aware that it will remove anything that is panned to the center. This video (although old) shows how to remove as much of the vocals as possible using FL Studio ("if you're lucky!").
With the extra phoneme "dx" it may be possible to make Eleanor sing in accented Korean (and Japanese). Not too sure about double-consonants.
I've tried just adding an extra consonant (example: /.k k aa/ for 까 based on the revised romanization), and it kind of works. I could hear a slight difference. I've also tried adjusting the tension parameter just so it only affects the beginning of the note, but it's too messy and too much work.