Refactoring? 
Thanks for lightning, it's a nice tool.
Trainer already has around 30 arguments and the PRs want to make it grow (see #516 and #539 for example). The more features, the more arguments and that's not really scalable IMHO.
There are things which could be grouped into objects instead, are you considering refactoring Trainer?
That would help the community see where the project is going and in which case to use it.