Calling GC.start with attachment_fu and RMagick -- where or if?

RMagick (and ImageMagick) have been criticized for memory leaks,
though the problem is avoidable by timely garbage collection -- see
this thread:

Attachment_fu does not call GC.start in any fashion that I can see, so
my questions are these: does it need to, and if so, where would be the
optimal place? It appears that
AttachmentFu::Processors::RmagickProcessor#with_image may be the right
method -- perhaps in the ensure clause? Somewhere else?

Or should GC.start be called in one's app at, say, the end of the
controller create method that uses attachment_fu -- instead of mucking
about with attachment-fu's lower-level plumbing?

Or does attachment_fu handle the needed garbage collection in some
other way so it's good to go as is? In a development environment app,
the attachment_fu/RMagick stack is working great, but I'd like to
understand whether I need to do something more before moving to

Many thanks in advance for any pointers!