Was this ever added back to the defect/bug list? The last response is from 2017, and I just ran into this scenario today.
We are self hosted on 8.79.1, and I had assumed that Text items always default to TXT as the set key and that it couldn't be changed. But come to find out that we can change it, but the change doesn't affect new items created in the set. Regenerating the IDs does force the IDs to change though, but as mentioned above, any items created after that process have the default TXT set key.
I am just going to tell our users we cannot customize that set key, but considering Project admins can change it and regenerate IDs, this is something that could cause issues later on.
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