I am fairly certain that mprep also uses some amount of automation in handling reports. It might not be to the extent that no human intervention is required for action to be taken, however, I strongly suspect that he uses tools to help him handle common report types quickly -- he certainly has the technical expertise (from what I have observed) to create said tools.
I do believe I remember seeing them say they have a way of handling mass amount of reports, though don't quote me on that.
When he handles consecutive posts and needs to merge them, I have noticed that the revised remaining posts always appear exactly the same (as a function of the posts being merged). I think it is probably safe to say that he uses automation for those reports.
Based on the amount of trash that has been in the altcoin sub over the years, I cant imaging it even being possible to be the mod over that sub without the help of automation.