How did Nintendo implement this? Did all 5 of the games actually contain it? I've never seen much research.
Common unconfirmed opinion is the lockout was due to missing character set.
See I placed those 5 Chinese games on supercard dstwo with US ds lite, then 3 of them boot. Even though they supposedly shouldn't... (Yoshi's Touch & Go, Wario Ware Touched, Polarium)
Yet place the same flash card into US 3DS, all 5 run! I don't see what difference could be causing this type of nice improvement.
The two for me which freeze on DS lite at the "only for ique ds" warning are Super Mario 64 DS and New Super Mario Bros. Any chance cheats or patches might disable the block? Since they work on 3DS it doesn't seem like a compatibility issue. Too bad that would mean finding volunteers with basic DS coding insight...
Anyway if you have other DS models, flash cards, etc, let's hear what happens to them. It might be useful info too.