If we assume it is the BMW turbo 4 cylinder the engine will be 2/3rds the length, so leaving quite a bit of space at the front = front/mid engined.
I'd hope the manual box is a no cost option....: would it also be lighter than the auto box?
The B58 engine is offered in a range of power outputs, up to 302bhp. To be honest, if they use the 302 bhp version what is the point of the Plus Six? The 255bhp version would be a better "fit".