Now that fix for LU-5718 has landed, there is a question as to whether that fix should be "off" by default requiring a module parameter to activate it.  This ticket is a place to "debate" one way or the other and to change the default to "on" if that is what we want.

I seem to remember a concern about the doubling of SGEs using memory causing problems for LNet routers which may be memory-lean.

Thoughts?