Is temporary functions feature official/supported? Found some issueswith it.

Hello,

Is creating functions in pg_temp schema something we support?
It's undocumented as far as I could see, but maybe I missed it.
People seem to use it.

I found that a combination of temporary functions and prepared 
transactions can lead to:
1) all other sessions being unable to create a temporary table until the 
prepared transaction is finished (reproducible);
2) data corruption in pg_namespace, server crash (happened a few times, 
but I'm not yet sure how to reproduce).

Is it something worth reporting in more detail?

Best,
   Alex