In the attached excerpt (galley mode) all three strings are getting a cue of another instrument’s gliss, which starts on beat 2.
The gliss is put in treble clef, per the instrument involved. This creates a temporary clef change for viola, as you’d expect.
The problem is that the viola is using alternating tremolo notation, and the second note in the oscillating pair is switched to treble clef to match that of the cue notation. This would probably be very confusing to player. (See the red circle in the attachment.)
Any suggestions for an elegant way to convey all of this?