Has anyone found a better vi or vim?
I found the answer:
it is in the repository and can be installed with opkg.
opkg list | grep vim
and opkg install the 2 packages.
you'll have to diddle around a bit in /bin and /usr/bin to apply links to the newly installed vim.
after that was done, I discovered that bash is also in the repository. I installed it as well since
I prefer it to ash.
Well done 
This is not directly an answer, but I find it simpler to mount the Yun folders on my PC and use the editor of choice (gvim) on my PC to edit the files on the Yun.
@NewLine
Could you please explain how are you doing it or give a hint.
Are you using netrw.vim?
Thank you very much in advance for your answer, MicMac.
Recover Yun OS by mount Micro SD on Linux box