IIRC Verity-Am has played a bit of 13 for the Force in past seasons.
Just checked the record: Verity-Amm first started a game for the Force against the Lions in Rd 10 2017. He played wing or fullback in seven of his eight appearances. Against the Highlanders, he came on for Ian Prior, who was playing at 10 at the time, but the backline at that time was:
9.) Ruru
10-15.) Some combination of Verity-Amm, Newsome, Meakes, Rona, Masirewa, and Morahan (basically 4 wingers, Rona (winger/13) and a 12).
Over the season, he had a 79% tackle success rate, but that doesn't tell the whole story. Some games he made 100% (9/9 against the Lions, 7/7 against the Hurricanes), some games he made 50% (2/4 against the Sharks, 2/4 against the Reds). It seems that he's either switched on, or not.
Offensively, his metres aren't great. 6.1m/carry, 36 carries, 12 defenders beaten, 4 clean breaks, his running game stats are more comparable to Pocock. Maybe that's what you want from your 13, but his defending is suspect enough that I'll say it's not worth the gamble.