Antigrav boots are only available every three levels. At level 42 you can get the antigrav boots which offer protection 57, which happens to be the same as the alternative boots available at that level. However, at levels 43 and 44, new boots are available, offering increasingly better protection than your level 42 antigrav boots. If you want to keep your bonus clicks from the antigrav boots, you will probably forego the extra protection offered by the boots for the new levels.
Furthermore, the antigrav boots at level 42 are the ONLY antigrav boots which are equal (in terms of protection) to the alternative boots available at that same level. The level 45 boots are -2 protection, the level 48 boots are -4, the level 51 boots are -6, and so on.
Anyway, those are reasons to want TWO pairs of boots and switch between them. If it takes too many clicks to reactivate them, this may not be a valid strategy. Thus my interest in finding out how many clicks it takes, and my interest in finding out if a higher level of antigrav boots can be activated by a lower level character!
Switching daily is probably not a great idea, but imagine saving up a few weeks worth of clicks (with the boots on), then switching to the better protection boots available at your level and going on a click-spending rampage. True, the advantage I'm talking about is likely a small on, but even the smallest advantage over a long period of time adds up to something significant.
Sandy