If you are recoding survey question IDs to simply make your data export variables comply with some standard across datasets or make it easier to analyze your final data, then the Qualtrics question ID recoding feature is probably for you. However if you are trying to use a more dynamic approach to processing your surveys using custom question IDs, then you might want to be aware then you cannot currently use your recoded question IDs within piped text.
I had recoded my question IDs because I had two blocks of identical questions but one block of the questions pertained to the left side of an object and the other block was used to answer questions for the right side of the object.
For example, block 1 would be for the 'Left side of house' and I might have the following question (where QID4 is the internal Qualtrics ID):
QID4. What is the quality of the foundation?
But I want to ask this same question on the right side the house, so I recode the question ID to 'Q1_L' for the left side:
Q1_L. What is the quality of the foundation?
The right side for question 1 would recode to Q1_R, and so on. Each question would have the same prefix but an _L or _R suffix to designate the side.
The problem with this comes when I'm trying to work with piped text for these questions, either in the survey flow or questions editor. Qualtrics forces you to use the internal QID assigned to the questions when working with piped text for the questions. So if I wanted to get the value of Q1_L, I could not use q://Q1_L/SelectedChoicesRecode (assuming this is a selection choice question) but instead would need to use q://QID4/SelectedChoicesRecode.
This simply makes it difficult to work with recoded question IDs. If you are building calculations that would be simplified by using the recoded question IDs (such as Q1_L + Q1_R = Q1 total), you are stuck using the internal question IDs ( which may look like QID24 + QID113 = Q1 total).
This becomes a quality assurance problem because you need to ensure you are mapping the correct internal question IDs to your recoded questions, and you keep wondering, does QID24 or QID25 map to Q1_L? Yes, the mapping of the internal and recoded IDs can be found in the survey csv data export, but it simply gets confusing while building a survey when you can use the recoded IDs in some places but need to fall back to the internal ID for others.