Why is it you make grammatical claims that somehow Dr. Wallace misses?
NET version
13:8 and all those who live on the earth will worship the beast, everyone whose name has not been written since the foundation of the world
27 in the book of life belonging to the Lamb who was killed.
Footnote #27: The prepositional phrase
“since the foundation of the world” is traditionally translated as a modifier of the immediately preceding phrase in the Greek text, “the Lamb who was killed” (so also G. B. Caird,
Revelation [HNTC], 168), but it is more likely that the phrase “since the foundation of the world” modifies the verb “written” (as translated above). Confirmation of this can be found in Rev 17:8 where the phrase “written in the book of life since the foundation of the world” occurs with no ambiguity.
The verb translated "written" is in the perfect tense.
"The perfect tense in Greek is used to describe a completed action which produced results which are still in effect all the way up to the present. " Therefore the completed action, names written in the Lamb's book of life, can still be found in the book at the present time, which is set at the end of the age.
So when was the action completed according to grammar? Up to the end of the age. And at that time all the names will have been written as a completed action, with continuing effect, everyone's name will be found in the book that had been written in the book.