News from AK2i official that now update AK2i firmware so that it can run DS games on 3DS is available.
Here is the user manual :
Please choose a update file to run depends on the type of your console.
1)"ak2ifw_update_3ds_v1_D Si.nds" for DSi and DSiXL.
2)"ak2ifw_update_3ds_v1_D SL.nds" for DSL and DSPhat.
3)Then follow the instruction on screen.
The first type of AK2i, which has a little window in the shell of back, can't update to support 3DS temporarily. The HWID of this type of AK2i is "44"