If you take an FW, and you deploy all your on-table baggage behind it, does that mean you can use the Delay Battle stratagem? After all, the concept behind the stratagem is keeping your army safe from battle behind camp fortifications until a time of your choosing. If a frontier wall isn't good for that too, what's it good for? (Don't answer that!)
And does the rule about 1-3 gates (page 11) apply to frontier walls, or only traditional town-like BUAs?