According to the version of the grammar I checked in,
we can already have a non-logical termset,
if we don't mind using forethought:
nu'ijo'ugi mi bau la lojban gi dy. bau la gliban. tavla do ti
(where I think the {nu'u} _is_ elidable).
Termsets _are_ the way to go.
Colin's use of {fa'u} balancing a {ce} (or whatever)
rather than another {fa'u} is interesting,
and yes, I think it _does_ work.
mi'e .i,n.