Hello; My take has been not to do any thing to a tank that is not leaking. I did not keep records but think that some of my tanks have been in use without issues for at least ten years and likely longer.
I do not recall any real warning signs that would have alerted me to pending leaks in the past. Leaks and failures have generally happened without any warning.
My approach is to try to place a tank so that a leak will not cause additional damage to the house because of the leak itself. I went to the trouble of removing carpet from the area of the tanks in my current home and putting down vinyl tiles. I also placed a barrier of half inch quarter round sealed with silicone along the border surrounding the tank area with a hole in the floor to hopefully give water a place to go.
In 50+ years of tank keeping I have come to expect that the water will make its way out in some manner, not only just from a leaky tank. Most leaks and failures have been of the slow nature with only a couple dumping a lot of water in a short time.
I have gone for very long periods without any water problems, but they can happen without warning.