Would it be too taxing to deadlift heavy 3 times a week after a track session? I'd also be doing Squats that day too. I was thinking no but others have told me otherwise...

What do you do in track?

Depends how your work capacity is. For the first few weeks, I;m sure it;ll be fine. But after a while, you're going to overtrain the movement. Which is why it's a good idea to use exercises like the good morning, reverse hyper, GHR, zercher hip extension, and other posterior chain movements. Same goes for the squat. Which is why there are front squats, back squats, zercher squats, etc.