If it's suggested as a handshake alternative in the context of human-to-human infections, then probably a namaste[1] is an alternative salutation more widely understood by people around the world.
[1] https://en.wikipedia.org/wiki/Shaka_sign [2] https://emojipedia.org/call-me-hand/
It also resembles the "please, I'm begging you" gesture in the US or a general prayer gesture.
I don't get the pointing at the heavens thing, I mean Jesus himself mentioned to basically be humble, not like those guys on the street corners making a bit show of praying.
I don't think there's a literal "canonical" position, but if you look at old art, the folded, non-interlaced position is definitely more common, with Dürer's depiction being already pretty late to the party.
To add Abrahamic confusion to it all, I think there's also some Rabbinical argument against it (or was it qabbalistic?).
Anyways, we're all wearing masks now anyway, so the appropriate gestures would be the Kuji-kiri.