RJ told in one of his Q&A a bit more about transmigration. Naturally there are time constraints to snatch the soul, especially considering balefire. However RJ also said: "there are a few other limits and constraints, but I won't go into them here, since I may want to use them in the books, and I would rather they come as a surprise if I do."

This RAFO concerning other unknown limits and constraints fits with what BS said on this topic at a signing:


Then BS still gave away, though, that the DO also couldn't transmigrate Sammael, because of Mashadar. So, this constraint doesn't seem to be one of the RAFO limits, which neither RJ nor BS specifically wanted to talk about.

Those RAFO limits and constraints, which are apparently other special circumstances of death, are still unknown (it could be linked to Asmo's death, because RJ cryptically said that Asmo couldn't be transmigrated because of how AND where he died).

I suggested that the DO usually might not be able to transmigrate a person, who dies in TAR, because the DO seems to have less power over TAR. An exception to this rule might be a close connection to the DO in TAR, at the moment of death, like Ishy had in the end of TDR.

Otherwise, the DO might also not be able to transmigrate a person, who dies in a stedding, since we know that the TP doesn't work in a stedding. Possibly, the DO also couldn't transmigrate Ogier, who seem to have souls, which aren't really connected to the WoT world (IIRC, Min never has Viewings around Ogier, and we know that Ogier never see any ghosts). Maybe the DO also can't transmigrate ta'veren or Heroes of the Horn, because they are too closely bound to the Wheel?

Do you have additonal ideas on the few other, possibly surprising limits and constraints or what circumstances of death (except for balefire) could prevent the DO from transmigrating someone?