It should have no effects on your rails. I have found that there are potential issues that can arise from using traction tires or any type of traction enhancer other than adding weight to the loco.
1. The loco warns you that it cannot make the climb by slipping. If you add traction tires / Bullfrog snot etc. the loco may make the climb but the added stress will shorten the life of the drive train.
2. If the lock becomes hung up on something it will stop the motor rather than allowing the wheels to spin. Once again potentially damaging the drive train or burning up the motor.
3. If too many cars are being pulled by the loco the first warning sign will be the drive train giving out.
I recommend adding weight to the loco. This added weight evenly distributed causes the wheels to have more traction. Decreasing the rolling resistance of the cars the train is pulling will allow more cars to be pulled. This can be done with metal axils and wheels.