I don't do it. The reason I don't do it though is for consistency. It seems there is a general consensus that whatever methods you use in your stringing, you ought to keep them the same every time.
If I increase the tension on tie-offs, I will inevitably forgot to reset the tension after I've tied off. I've done this multiple times. I've finally settled on simply not messing with the tension (with the only exception being if I'm doing a different tension for mains and crosses) at all when I string. For me, that helps achieve better consistency b/c it is one less thing I have to remember.