If I get the plug in will that deal with the issue if the piece was edited in 29.97.
Nope.
And, there is nothing lesser about using the native
method in Ae that is described in the link above.
my best guess would be is that it was edited in 24p as it is a very recent feature.
My best guess (if it was shot on film @24 and transfered in telecine to 29.97)...
it was probably edited @29.97.
Is revision the better way to go in geneal?
I assume you mean reverting to 24p... it depends on what you intend to do.
For example if you have 29.97 with 3:2 pulldown inserted and need to do
a composite with that clip, it is imperative to remove the fields.