Vis-a-vis has multiple meanings, which are:
- in relation to (if used as preposition)
- opposed to (if used as an adverb)
- face to face meeting (if used as a noun)
- a counterpart (if used as a noun)
Deciphering which one you meant, especially for someone who is not perfectly fluent (and many natives as well), might be a nightmare.
There is a reason we try to use simple straightforward English in business settings, and that reason is to reach a broad and diverse audience with varying levels of fluency in the English language and present information in an easily digestible manner.
If I was forced to read flowery business prose containing gems like this, I'd probably silently curse the author and would not give him a nice review. Want to use language like that? Write fiction!
I do love to read and listen to Shakespeare and Poe, but that does not mean I like to stop reading every business proposal to Google the meanings of phrases used.
Business English (aside from marketing and corporate-speak) is there to be simple and to the point, to give you a clear image without the need of being fluent in English.
It's basically there to be a step up from pidgin English and waving your hands frantically to simulate your need for water/food/currency exchange/your desire to build a new oil platform off the coast of Belize...
That is, sadly, my definition for it.
But man proposes, nature disposes and in the end, the business communication will use whatever it can get away with.
Are you writing a document for a company of English language majors, you yourself being one?
Go on, let them know of your knowledge of the Queen's English.
Are you a Chinese businessman who built himself up from a store clerk to a head of a multinational corporation?
Use English first-graders in Central Europe would be chastised for.
In the end, what you can and can not use will be shaped out of your own limitations and the limitations of your audience.