The lesson re small trailing Katakana 'vowels' was very excellent, and the list
of supplementary Katakana is excellent; which Katakana spelling for violin do you prefer?
The only such Katakana seen much at all seems to be the one for creating a 'v' sound, so
the list is very nice! Most people seem to simply pronounce a 'v' sound more or less like a 'b'
sound anyway, such as the Katakana for Convenience Store.