The switch should be physically the same size as 3-way's and 5-way's. I've never needed to mod the cavity to make it work.
As to it being worth it, it mainly depends on what pups you use. Some play nice in series, and some don't. You almost need to try it hear for yourself. The good news is, changing the switch in a Tele is one of the easiest jobs in all of guitar work.