Craig: This is probably not possible in verovio: the problem is that the triplet and the beam cross over each other. This should be possible within the next year with verovio, however, and will be encoded using "beamSpan" rather than "beam" and/or "tupletSpan" rather than "tuplet". It will be interesting to look at the original score to see if the notes are beamed in the same manner.
annawright18
commented
4 years ago 
Berg 453 - R453_Ber-w15p362-363m118-121
Craig: This is probably not possible in verovio: the problem is that the triplet and the beam cross over each other. This should be possible within the next year with verovio, however, and will be encoded using "beamSpan" rather than "beam" and/or "tupletSpan" rather than "tuplet". It will be interesting to look at the original score to see if the notes are beamed in the same manner.