Preview macro doesn't mean, that the feature has bugs. It means that the feature is in a stage of collecting feedback from the users, so interfaces, as well as implementation, can be changed.
However, recently, due to the number of requests, we have started work for Memory Pools productization. I can't say the exact dates, but we are working on it.
Mem alloc/free is always a big headache for c/c++ lang. One of the major pro of the pool concept is that once you do memory alloc on a pool, you can free the pool as a whole, you don't need free memory piece by piece, which reduces the chance mem leak/crash, in case your forget to free or you free duplicately. Thanks.