Spamming it would be insane knowing that the little guy can take Nikaido back in time by 10 seconds at most. I did the math, just for the heck of it, and it would take 72.5 million time travels to bring him to the years when he started playing golf (or double that if the limit is only by 5 seconds). Much like Nikaido said, it's a shitty power but can be somehow very useful in sports like golf.
I admire Fukumoto for seemingly using time travel in one of his stories, and being very limited with such powerful gift. I'm now beyond curious if something cruel or intense is going to come out from it.