Absolutely
I have more mixed feelings about this. The title field is first and foremost a primary identifier. There are times when that can also usefully be descriptive text. But often for data-heavy wikis, that makes little sense. But you can nearly always use the caption field for that.
I’d be very concerned about the proprietary nature of w3w. If you’re using it to store both coordinates and three-word addresses, read carefully the restrictions in Section 6.3 of their API license agreement.