Games & Gears has a kickstarter going at the moment for 6x4 modular tile battle boards. One of them is a 10mm scale city field for Dropzone Commander that they specifically mention in the Questions section at the bottom
Is Robotech Tactics and other 6mm miniature wargames a good fit on the Dropzone Commander Cityscape battle board 10mm Scale?
Yes, this has also been verified by hard core 6mm gamers of various IPs who have confirmed this via our comments section. We also check at Gen Con and works really well. The difference between 6-10mm is so small (4mm) The battle board just fits nicely in that realm.
Cheap too, worth a look.