I have looked at the help for update.packages(..., checkBuilt = TRUE) and I am unclear on why one would not want to have TRUE as the default. The default is FALSE.
This question has two parts. (1) Can someone give a clear explanation of the use of this argument and rationale for either FALSE or TRUE?
As I understand it, if one updates R, then this could have different outcomes - if the packages haven't been updated, then FALSE will not cause the local libraries to be modified with updated packages, while TRUE will cause more (all?) packages to be updated. The default option (FALSE) may confer a speed benefit - fewer packages will be updated. Stability is uncertain - a new version of R may work better with a new package, or it may not (e.g. if there are regressions / bugs in the new package), and it may or may not work with the earlier version of the package (backward compatibility is not guaranteed). Other pros and cons are not obvious to me. (And I may be quite mistaken here - which is why I ask for a clarification as part 1.)
(2) However, if one has not changed the installed version of R, then shouldn't these have the same outcome? See this post for an example where it seems that just calling update.packages() created problems, even though the version of R did not change.