I'm not sure if it is perhaps also difficult to implement, but I find not supporting sum record types because they are bad practice, as you put it, a bit arbitrary. I'm currently working on a project where I want to serialize somebody else's types which happen to contain a sum record, but now I'm stuck.
I would also make the argument that it's not that bad, even GHC itself has a few examples.
I'm not sure if it is perhaps also difficult to implement, but I find not supporting sum record types because they are bad practice, as you put it, a bit arbitrary. I'm currently working on a project where I want to serialize somebody else's types which happen to contain a sum record, but now I'm stuck.
I would also make the argument that it's not that bad, even GHC itself has a few examples.
Let me know what you think