Fear of being promoted too soon - imposter syndrome vs fear of being overworked

Hey all, 

Bit of an odd one. I work at Strategy& (Tier 1 NA office), where I joined as an A just over a year ago. Since then things have been going really well and I was promoted to SA earlier this year. 

Thanks to a strong internal reputation and network, and the business doing incredibly well, I was told that promotion to Manager at the next cycle is not unreasonable if I push and keep searching for stretch roles.

Consulting is not an end goal and I long to exit into FANG or similar (I have a STEM degree from HYPSM). Do you think I should be pushing for the role? Will there be any advantage in a Manager title when it comes to exits?

I do not necessarily think I am ready and I am concerned that it may result in overworking to compensate. The spectrum of M competencies is quite broad, while I already feel I can do as good a job as some of the current Ms, this is far from doing a consistently and objectively good job. They are hiring people at an unprecedented pace, particularly at graduate level, and I feel they are pushing people that are not quite ready yet, and I feel in this category.