Is this existing or new construction? The light gray lines indicate what exactly?

New Construction of second floor.

In my previous house the MB door was at the top of the stairs just like you're showing and it never bothered me, but what you're showing as an alternative looks fine, too. I don't think double doors into a bedroom have much utility so don't do it unless it's important to you.

"The light gray lines indicate what exactly?"

And?

Gray lines? as in dotted lines? Those are elements of the first floor. Attached for reference.

If it involves an existing structure it is a remodeling and/or an addition. The existing structure and other conditions greatly influence the remodeling and/or an addition's design. Much of the information needed is impossible to communicate over the internet and you are better off relying on someone local that can visit the site and gather the information themselves.

There seems to be a lot of inefficiencies in the layout, but I do not know if that is constrains imposed by existing conditions or poor design choices.

Can you create a small, recessed alcove? It would reduce the bedroom's square footage a tiny bit but it might solve your problem.

What inefficiencies are you seeing here? The second floor will be brand new.

The dashed lines on the 2nd floor appear to be the layout of the existing 2nd floor. The house footprint is being stretched out with the interior being completely rearranged, and the 2nd floor expanded along with that. Showing that many demo walls on a proposed layout drawing is confusing and unecessary.

If you want a double recessed Master Bedroom door, you would have to tweak the Master bath and closet with that. The bedroom proper is 16'-9"x18'-2", which might be a bit large with too much empty space, so the 18' length could be reduced to 15' to help in your door dilemma.

(By the way, in the hall bath, make that a one-wink vanity, with two nice banks of drawers. Counterspace and storage will be more appreciated, and if two kids ever are in there brushing teeth or shaving at the same time, they will learn to share! My two boys were never in there at the same time, and they both used the same sink. No one want3d to use the sink closest to the door!)

Have you considered swapping the laundry and hall bath? It makes the bathroom more convenient to the bedrooms it serves, and centralizes the laundry for all, including making it a bit closer to the stairs for running up and down to swap clothes from washer to dryer.

I'd avoid a double door to the master bedroom. Hard to situate light switches properly in such a case. A single door is functional and works wonderfully.

Go with @bpath for sure.

Unless the double door entrance can be the size of 2 full doors, it never looks good. It will feel like the little swinging pub doors. I think it is fine the way it is or push in a little like shown above.

Good luck!!

The only time I put double doors on a bedroom was in a patient room in a critical care unit.

Layout all the furniture to scale in every room to get a better feel of how big they are.

Recommend you check these bathroom design guidelines: http://starcraftcustombuilders.com/bath.design.rules.htm And try a mock setup and usage of a bathroom sink right next to a wall or in the path of a door swing. You'll see it's so inconvenient and uncomfortable that it will never be used.