Cool, thanks comrade.
Running it gives me
25 non-free packages, 2.1% of 1173 installed packages.
1 possibly non-free packages, 0.1% of 1173 installed packages.
Using --strict, it looks much worse:
109 non-free packages, 9.3% of 1173 installed packages.
107 possibly non-free packages, 9.1% of 1173 installed packages.