This tool does what you want:
http://www.renoise.c…eral-note-tool/
It might have some culprits, but you can expand or dimminish the code as you please.
The only modifier shortcut still free regarding the enter key was with shift+alt, this seems to work.
As soon as you have filled in the full notevalue, it is being instantly applied. If the notevalue is incorrect, it will be autoadjusted.