You can set heat tape up many different ways.
If it is one long piece only one tstat can be used.
If you have a piece for each level then each will need a tstat.
In my opinion a small difference on each level is fine. If my "hotspot" is between 83-86 I am happy. Hardly any of my snakes use their hotspot and being so I turned many of them off and will only use them during colder months...if then. None of my hotspots are set higher than 85 or to a temp that gives a 85 degree hotspot.