Hello @kemmyb. Yes, the sweet potato already has natural sugars. In fact, you can eat it raw. However, the taste is plain when boiled in water. Adding a quantity of sugar caramelizes a coating on the potato.
Just like any other pie that you first boil the fruit as in strawberries, peaches, pears, doing so reduces the fruit to a consistency of jam or jellies to bake in the pie shells. And yes, the pie shells taste as good as the homemade ones, if you purchase a name-brand, such as Pillsbury or PET.
Remember, each of the ingredient as baseline. Some like less or more spices. So, the saying is "add to individual taste."
Let me know how your pie turns out. Thanks for your visit and lovely compliment. I appreciate it and your support.
P.S. I made two pies, and my husband has already eaten one of them! Coffee and pie for breakfast. But these are the holidays!
!ALIVE