Anecdotally, I'd say a lot of non-engineering firms see you having an MEng over a BEng as more valuable and will give you an advantage for it. They won't question why you didn't do an MEng if you only did a BEng though, it's icing on the cake rather than an expectation or in the range of normal.
That said, if they know they only want a bachelor's graduate then you're going to lose out for being overqualified.
I would also strongly avoid doing an MEng if you don't want to go into engineering afterwards, it won't go well.