I find that in the early game there aren't enough worker turns to make this practical, although in theory it would be great if you could do it. Despite my reputation (and well deserved) for neglecting micro I do a lot of early game tile-swapping as IMO it's kind of necessary at high levels (I've gotten to the point where I can outright remember what tiles I'm working in which city when we're talking 8-10 cities or less).
My goal for the early game is usually to make sure I have enough workers that my cities aren't working unimproved tiles (other than the very brief period immediately after founding for aggressively settled cities, and of course the turns building the 1st worker).
Once expansion to key areas (to beat the AI there, or to get enough military to pull a rush) is done, more workers can then help with tile swapping options, but the priority seems to be getting the cities at all that early without tanking!