Sure. It's similar to a lot of things in life that can get 'boring' because you get used to them. Take cooking, for example. After a few years of the same 23 meals, you try something completely new. In the already intense bhakti known as kavadi, most regular annual practitioners add a bit more (another piercing or two) each year, until around age 50+ or until they don't feel the need to do it any more, or their physical health can't take it.
Or ... another example. I was a parent at a short talk by Canada's national swim coach once upon a time. He explained that once an athlete gets complacent, or thinks they're really good, they just put them up to a more advanced level. That will up the practice intensity, and once, if ever, they arrive at the international level, intensity is no longer a factor. (Just as intensity is no longer a factor for the Self-realised being)
But how this intensity is increased is on a personal level. My Guru's words on it were 'do a little extra'.