Yes, that's right, toe will not be correct at 30 degrees. In fact, it should NOT be equal at 30 Degrees. This relates to the "Ackerman Theory."

Think about it, when you are turning, the inside wheel is turning at a different radius than the outside wheel. If this were not compensated for, your tires would scrub like crazy every time you turned.

The Ackerman Theory involves an imaginary line from the center of the line going between the two rear wheels. The line stretches from that point to the steering pivot(ball joints or king pin.) Perfectly aligned on this imaginary line should be the center of the outer tie rod end. This is all, of course, with the front wheels straight. If this line is correct, then the front wheels will turn at different, but correct radii and prevent tire scrub when turning. This is not something you can adjust, it is designed into your car.

The toe is set to zero, and the wheel centered, by whatever means, preferably so that the steering wheel is straight and at the center point of the steering box action. The box is designed to be tight at the center, but has a little more slack away from center. With the steering box and steering wheel centered and toe set, loosen the tie rod sleeve locks and turn both tie rods equal amounts in the same direction to point wheels straight forward. Without fancy alignment equipment, this will involve a little cut and try and then test drive. Once the wheel is straight, recheck toe to be thorough.

Good luck,