A question for Vaidikas or those who have had an opportunity to hear from Vaidikas:
“Why does the Veda’s Nityatvam/Eternity (or at least the fact that it existed before the world) *for you* contradict the ideas of layers & relative chronology in the Vedic Canon?”

If a Deva’s Nityatvam beyond time & His taking avatāras in real time are not contradictory, the Veda’s Nityatvam (or pre-existing the world) is also not injured by its growing in history over time.

It follows that all perceived contradictions in this regard spring from a lack of commitment to the idea of Veda as a deity. As long as you analyse the Veda as just a text, you will keep “defending” Veda’s Nityatvam against historical insights.

See the Veda as a Deva or Parabrahma, your misgivings about the historical approach will slowly vanish.