I understand that this would be a bit controversial. Imhp as possibly ignorable suggestion, it'd be more helpful if the Tuple supports BgDecimal numeric equality rather than simply checking object.
In a particular case, you may want to check if a collection of pairs contain a certain pair which includes BigDecimal values. Then to check object equality is maybe just right or not. But in many cases, I assume that numeric comparison would be more demanded such as following simple example.
I created the PR. Please take a look. I'm happy to whichever it is accepted or not receiving feedback.