Is this by design or a bug? Here is an example that is causing some heartburn. In a survey I have a repeating group that is conditionally required. If the user doesn't need that section it is not shown. However I am still seeing a record being inserted into the table. If the repeating group is not relevant I wouldn't expect it to insert a record into the table.
To explain further here is our example. The questions in the repeating group are related to how many plants were counted in the sample and how many plants were found in the sample that are affected. i.e. They count 500 plants and found 2 with the condition we are looking for. We default the values of those questions to aid with user entry to 500 and 0 respectively. When the record is inserted for the repeating group that is not relevant it inserts the defaults of 500 and 0. Then, when I look at the data it makes it appear that they did the counts and found 0 affected plants.
From my testing I am seeing this behavior in 3.3 and beta versions of 3.4.