I tested it in a viartual box and it seemed very trade-free. The only thing I found was the default search engine in the browser of Trisquel which is Duckduckgo. Duckduckgo is not trade-free since they put ads in their search (https://www.directory.trade-free.org/rejected/duckduckgo/). I’d recommend them to use one of the SearX Instances (https://www.directory.trade-free.org/?s=searx+instance). Maybe I’ll contact them about that.