Since you're already diverting into TEXT when you expect the overflow to occur, you have to use a diversion trap instead of a page trap:
.ll 20m .de CUT .di \" stop diverting into TEXT... .di TEXT2 \" ...and divert into TEXT2. .. .di TEXT .dt 1v CUT \" 1v into the diversion, redivert into TEXT2. A paragraph that is long enough to be used as an example for my question. .br .di .nf .TEXT ----- .TEXT2 .fi
