... on Henoch and Elijah or Moses and Elijah

Elijah the Witness
Sword of God .Second channel
https://www.youtube.com/watch?v=vUUdY7mIGJg

I (not first, but most important)

Malachi 4:2

Sun of righteousness = Our Lord Jesus Christ
With Healing in His Wings = His arms were streched out on the Cross

II

Time traveller?

If Henoch and Elijah were lifted up and will return as the two witnesses, this does not mean they are fast-forwarding everything that went between. But of course being lifted up to Heaven (whatever level of it, as long as it's supernatural and not just - even that doubtfully - a few days on the moon) means that forgetfulness no longer has a grip, and that their experience between the lifting up and the return down will not have made them forget what they saw while on earth.

III

Why Henoch rather than Moses for second witness?

Two reasons. The two witnesses die. Moses already did die, since Michael and Satan were arguing about his body. One reason for not Moses but rather someone who was taken up alive.

Apart from fitting that description, Henoch is also ancestor of the Gentiles. That is not the case with Moses.

Precisely because Hindus are Gentiles, not Hebrews, and because the ancestor of Pandavas and Kauravas "Bharata" was both an empire founder (like Cain with his son Henoch) and receiving "Nirvana" (which is not being taken up into Heaven, but kind of a substitute concept among Hindus), I wonder if Henoch (the Patriarch, not the Cainite King) will not when returning be either confirming or infirming my guess. Precisely to the Hindus. That might make some of them convert.

IV

Your argument for Moses:*

These have power to shut heaven, that it rain not in the days of their prophecy:

seems to be the power of Elija

and they have power over waters to turn them into blood, and to strike the earth with all plagues as often as they will.

seems to be the power of Moses. BUT we do not know what exact things Henoch did. Have you checked in Mahabharata if any figure (maybe mistaken for a god by the Pagans) has similar powers?* I say this since it is commonly understood by Church Fathers (I have not checked - perhaps St Augustine long ago - but otherwise I would not be seeing this in Catholic Bible Commentaries) that Moses died, so on Mount of Transfiguration Elijah came from Heaven, Moses from Under the Earth and the three Apostles from Earth. So, Moses seems to have died already. Apocalypse 11, BOTH witnesses will be killed. Fits with Henoch and Elijah.

Douay Rheims Bible Online
The Apocalypse Of Saint John (Revelation)
Chapter 11
http://drbo.org/chapter/73011.htm

* Though as Christians we do not need Pagan myth to settle interpretation, such a thing would be handy.