New(ish) three umpire mechanic

[JCurrie]

I was reading my Baseball Canada Manual for Three Umpires, and I noticed a new mechanic that has supposedly been used in CCA and/or PBUC for the last year or two. With two outs and U3 inside, he is now supposed to leave the outfield to cover a fly ball to his area.

Would anyone like to share their experiences with this new mechanic? It seems like a train wreck waiting to happen. I can imagine numerous scenarios in which U3 goes out with the ball, and U1 is left to sprint into the infield and cover a play at second or third. Even if U1 reacts immediately and begins heading to the infield, the runners are moving on contact and I foresee him having to call a lot of plays from poor angles.

I'd love to hear your experiences with this.

I also apologize if this has been discussed, but I wasn't able to find any previous threads with the search function.