The airfield I am learning at I believe to have VASI, but I have never ever seen it switched on. The CFI has decreed that it be kept off for the very reason you mention - that when you are watching the runway carefully you can't help but notice it, and it would be a disservice to learners to let them become reliant on it.
If your airfield is quiet enough, and your CFI is a nice enough chap maybe he would be agreeable if you suggested something similar, though I am not sure how this might affect licensing considerations if its published as being available
