I remember reading elsewhere that 2.7k was recommended over 4k since they are the same bitrate, so you're actually getting more detail/data in the 2.7k stream?

Of course with the 4k you can crop or apply digital zoom type of effects, but seemingly the quality wouldn't be as good?

Is this indeed the case?

It's 40 or 45Mbps.  Can't remember since I don't use it (tried it out a few times).  The Mavic really shines & was intended to shoot in 4k30.  All the specs lead to that & shooting that footage allows you to do whatever you want later.  The zoom is not smooth at all & the way it is implemented makes it a very forgetful feature.  So, zooming & only 720 beaming back to you are the only drawbacks I think worth noting (can't zoom or have 1080 live feed if shooting 4k).

Yeah, 2.7K/30 is 45mbps. I read a post that claimed detail was better at 2.7K, something about 4K really needing more than 60mbps to get an optimum quality/compression ratio, but I actually haven't tested that assertion myself. 2.7K looks plenty good to my eyes and saves space while I'm learning.

I do expect once I get some experience under my belt I'll switch to 4K and see for myself -- certainly like the idea of being able to zoom or crop in post while keeping decent res.