Yeah dinosaurs are always a significant issue, though I'm not sure it'll be as big a danger long term as it might seem, since I am intending to add in a lot of small cost sinks, and I don't think it'll be overwhelming by the time other sinks come into play. I could be wrong, but offhand rough math with the anti-dinosaur cost scaling means it would take 56,250 xp to raise each available skill to 5, which at 30 xp a week would take 1875 weeks or 36 years of play. And then the character would die of old age and the xp would be gone.
Funny numbers aside, I always will be concerned about dinosaurs and making newer characters feel overshadowed but I think it might not be as big a danger as it seems at first glance. I still intend to address it to make certain it doesn't scale in a way that's too disruptive, and I don't think it's gonna be nuts before those systems come in.