Sorry, but absolutely not. Minor toe change is a usually unavoidable, but you shouldn't see big changes. My race team had an issue with wicked bumpsteer on our MR2 at Eagle's Canyon several years ago. We had a "bumpsteer correction kit" that didn't play well with the lowering kit, and we were getting drastic toe change, causing the car to dart a foot or more on bumps, at speed.it's normal to have the toe change drastically from no weight on the suspension to weight on the suspension.
If any of your steering parts are out of place, making your tie rod angles wrong, you will get wicked toe change and bumpsteer. Did you install the tie rod ends into the tops or the bottoms of the knuckles? They should come up from the bottom. It should be obvious from the taper, but I've seen crazier stuff done. Our bumpsteer correction kit moved our MR2 tie rod ends from the top to the bottom.
Check to ensure you have the spindles on the correct sides. Make sure the steering center link is installed correctly. Make sure all your parts are seating fully in their tapers.