Here are a few things I’ve noticed, I don’t think they’ve been posted yet.
The bolt-action rifle can’t be unlocked. I’ve unlocked everything but it and it doesn’t give me the option of unlocking anything after battle anymore and it never appeared as an option.
Missiles are possibly too powerful, especially the incendiaries. My medium tank with incen outperforms everything by a wide margin, often getting ratios of 10 or more on the total/supply cost screen.
The description for the Dunkirk medal suggests you must have 200 infantry make it to the end when attacking, but I got it without deploying a single unit of infantry.
Infantry don’t fire often on the attack because their cone of vision is always looking straight ahead. Even with an ambulance they seem to die too easily without doing much damage, so I never take them on attack.
It is possible to make impossible units by making a text file with whatever components you want. It doesn’t help out tanks or mechs, but you can make super-powered infantry. I made an infantry unit with incendiary missiles, and while it was hilariously expensive (about 3500 pts per unit), it was also completely devastating.