I'm afraid this might be a problem for any choice of the verb to some extent, as nothing comes to mind that would exclusively imply "the context of concurrency" especially in terms of their general meaning in English.
Unless it's explicitly (and verbosely) spelled like isolationtransferring or actordisconnected, it looks like there'll always be a potential to ask questions like "passing from where? Transferring between what? Sending where to?" etc., so it's likely just not achievable to have a term that "reads on its own" and replaces any supplemental documentation / education on its purpose.
I vaguely remember the discussion for the original Sendable where it was also regarded as potentially too generic (which is why my original suggestion was to hammer on that one because at least send*** already has a recogniseable learned meaning here).