By default it is stored in ~ (for most up-to-date SFOS devices that would be /home/defaultuser)
I have an open ticket that sailjail may be interfering, since my install is very old I never noticed this, but I will probably be implementing both sailjail and the backup thing mentioned by Andy.
As for standardization -
Since there is no technical reason to standardize and all podcast clients don’t care what the podcast maker hands them there is no pressure to do anything, if anything the pressure is opposite, if I would do anything I am probably harming more users than I benefit (and putting myself in a crazy complicated mapping scenario where I have to map my renamed files to the RSS feed and deal with detecting a ton of edge cases because I am not doing what everyone is doing).
When I was a student I had a flatmate who was annoyed by this in the torrent naming schemes being different between different groups, he ended up writing his own program to standardize his downloaded filenames.