No data tooltip or function parameter autocomplete help appear for non-base R package functions. Sorry maybe I'm missing a setting but both work for base R functions so I'm guessing not.
If in my R code file I've e.g., library(edgeR) then in a line of code e.g. dge <- DGEList(...) when I hover over or mouse cursor stay on DGEList I don't get a popup data tooltip. And when I'm inside the parentheses it doesn't know or help with the available parameters, default values, etc.