update of a R package which is lazy loaded

I have several unix servers using a R package which is installed on a shared R library folder. The packages are lazy loaded (that's the default) from this shared folder.

Now I want to update the package:

1) is it possible (and clean) to do that without closing all R instances?

2) More precisely, I am concerned about the following:
2)a) The warning I get from the user interface when I try to install a package that is already loaded:
2)b) From https://cran.r-project.org/doc/manuals/r-release/R-ints.html#Lazy-loading,

When a package/namespace which uses it is loaded, the package/namespace environment is populated with promises for all the named objects: when these promises are evaluated they load the actual code from a database.

Does that mean that the R instance will read again from the library folder when doing the actual evaluation of each object (in which case that means I need to either deactivate the lazy loading, or close all R instances before updating the package)

3) is there an alternative way to maintain R packages on a network of servers, that are running scripts all the time, without having to put each server offline one by one)

Thanks for your input

You asked

1) is it possible (and clean) to do that without closing all R instances?

and I can assure that yes, that it is how works and done everywhere.

As for

2) More precisely, I am concerned about the following:

you are reading it wrong. An R restart is simply recommended to ensure the new package is loaded as you cannot insert it into a running session.

Further

3) is there an alternative way to maintain R packages on a network of servers, that are running scripts all the time, without having to put each server offline one by one)

you never have to take a server off-line just to update a user-space package. E.g. we don't even take them off-line when we, say, upgrade the entire Ubuntu release twice a year.