@yourfriendkarol
Currently no, you can use custom interface if you have BAS premium using your third-party to resize them. How ever, setting the startup window size for either interface is not a feature yet. fingers cross hope it comes soon tbh!
when I am in record mode BAS sometimes steals window focus when performing tasks.
It also steals global key binding. For example F2. When I am doing something else in other windows and press F2 nothing happens but I see browser in BAS reloads. I have multiple BAS instance opened (each in different folder) Win 8.1 64-bit
This issue is known. Corrected in the upcoming patch.