Currently, in mint_hashcash.py, the bit size is hardcoded to 20 bits and the compression is hard coded to '2'. These should be set as variables by the user, depending on their hardware, and what they consider to be "good enough".
It should be mentioned that the default bit size for Hashcash is 20 bits, and the default compression is '0', or no compression.
Thoughts about creating a ~/.pennyredrc for this options? This would be the "easy out", but I can't stand dotfiles in /home/user. ~/.config/pennyred/pennyrc wouldn't be too bad, but even then, I'm not a fan. These are plain text scripts, so the user could just put them into variables, and keep everything in the script. Either way, the user will have to add the values somewhere.