Perhaps Marks answer is better, but I only use Vanilla Acad and the only entity I know of that supports lat-long information is a POSITIONMARKER.
In the past I did some experiments with FIELDs on this object, but after that Acad wasn't stable any more.
What's possible is though, is to use text. So what you can do is to write a function that updates all POSITIONMARKERs at once with the values of their lat-long property.
Because POSITIONMARKERs aren't documented, I had to do some reverse engeneering (see attached file).