The LDS answer holds up. Do not lead with this one.
3 Nephi 11-28 has the risen Christ come down and minister to the Nephites in the body for days. Against that, Acts 3:20-21 calls Jesus one "whom the heaven must receive until the times of restitution of all things." So, the argument goes, he cannot have been in America.
The New Testament records him appearing after the ascension more than once. To Stephen in Acts 7:55-56.
To Paul on the Damascus road in Acts 9:3-6 and 1 Corinthians 15:8. To John on Patmos in Revelation 1:12-18.
Where Christ resides between the ascension and the last day. It is not a rule against him appearing.
Their reply is simply correct here.
FAIR gives exactly those three appearances and says the Nephite visit is the same kind of thing on a larger scale. They also read "other sheep I have" in John 10:16 as Jesus anticipating it.
Do not use this one. There are real problems with 3 Nephi and they are covered elsewhere.
Acts 3:21 is not one of them, and using it will cost you your credibility on the cases that do work.
Nothing. If someone else raises it, say plainly that you don't think it holds.


Christ appeared after the ascension to Stephen, Paul and John, so the verse permits it.
Apologists reply that the New Testament itself records Christ appearing after the ascension. He appeared to Stephen at Acts 7:55-56. He appeared to Paul on the Damascus road at Acts 9:3-6 and 1 Corinthians 15:8. He appeared to John on Patmos at Revelation 1:12-18.
So Acts 3:21 cannot mean Christ never appears before the restitution. It describes where he resides, not a ban on visits.
The Nephite ministry is claimed to be the same kind of appearance at larger scale. And 'other sheep I have' at John 10:16 is read as Jesus expecting it.
Do not use this one: their reply is simply correct, and it will cost you.
The strong reading of Acts 3:21, that Christ makes no earthly appearance until the end, is defeated by the New Testament itself. He appeared to Stephen, to Paul and to John.
Whatever other problems 3 Nephi has, and they are covered elsewhere, this verse does not rule out an appearance.
Christians should drop it.