Even though the Formless Path doesn't have a lot of rules, a common practice is to meditate or process information only while simultaneously doing something else that serves no purpose at all. There are milestones that indicate that you have a lot more free time than originally thought or that you have more capacity to process more things faster but for the most part these kinds of outward activities are only used to show that you aren't abandoning something you should be doing or some obligation you have towards others that is going to cause you or others problems in the long run.
One reason for having people do things that seem kinda useless is to see if they can get away with it even when they aren't processing anything too major. Because once people start seeing you having results it can turn into Cinderella's dress in that all sorts of people start showing up saying you shouldn't have had time for this because I needed you for this and that. But if you can read a pile of books that have no relevance to anything going on on this planet, or get to level 280 in Endless Bejeweled its pretty hard to say someone really needed you for anything at all. And if you do both plus other things that even the people who would object say was a real waste of time then you have plenty to tell people if they try to claim they needed you for something in the past or need you for something more important now.