For those wondering, RNG abusing on a 3DS seems to be about the same as RNG abusing on a DSi (you have to use the stylus to set the 3DS time, but like on a DSi you can hold the stylus down, and release when you're ready).
One notable exception: It takes significantly longer to go from the system menu to in-game with a 3DS. The absolute quickest I can get in-game to do a soft reset is ~32 seconds, whereas on my DS Lite I could get in game for a soft reset as quick as ~18 seconds.
Also you cannot suspend a standard DS game on a 3DS, like you can 3DS games.
My initial calibration on a 3DS with EonTimer is -39, which is very close to what my DSi XL was.
And no, you cannot play Japanese Pokemon Black on a US 3DS (although you can play Australian Pokemon Black on a Japanese 3DS, go figure).
As noted, only C-Gear RNG abusing is possible at this time.