as rob says, you can control that effect, but it's perhaps worth noting that
with acme, because each frame carries its own directory with it, it's quite
common to have one big acme window set up once and edit everything from everywhere in it.
remake in any given directory by typing mk (once for all) in the tag of that frame
and clicking it with button 2.  when using rio windows as well, perhaps
to develop or debug a graphics application, files are sent for editing using the B
command (it's documented with sam(1) but because it uses the plumber, it
will send files to acme too if that's what you're using).

using it that way, i find that acme thoughtfully keeps track of all the things i am doing,
at various stages of interruption; on the other hand, it conveniently offers email in
the same environment, which can lead to further interruption (but it's still highly
convenient).