The small profits you might make will certainly be outweighed by all the reporting requirements.
I don't think this is true at all. If you simply buy and hold, then the reporting requirements are not onerous at all (or indeed, non-existent until you sell or trade your bitcoin), and you will make a much better profit buying and holding bitcoin for 10 years than you will holding rapidly inflationary USD. There is also a bill kicking around Congress which would exempt all bitcoin transactions under $200 from tax, which would mean bitcoin can be used as a daily currency for the majority of people without having to worry about tax reporting.
In that case, hopefully other prison inmates accept bitcoin and you can have a way of sending it to them inside the joint.
There are many scenarios in which someone is not a prisoner but still has their assets frozen by the government. Recent examples include loads of private Russian citizens around the world, and a bunch of Canadian and US citizens who donated to the Canadian trucker protest. Bitcoin solves this.