The load-bearing structure of the staircase

[jamaica]

I had planned for those of us with limited storage to make use of the small space under the stairs, so I broke up the gypsum there.
I want to saw off the encircled blue stud because otherwise, it will be a bit cramped and awkward.
I'm not 100% sure it's not load-bearing, even though, as fairly inexperienced, I don't think it is.
Is it safe to saw it off at an angle along with the carriage of the stairs that's behind the drywall?

Edit: There are two half-stairs, so it's the lower one straight ahead I'm asking about.

 

[Småbrukaren]

Is the wagon piece anchored to the rear wall?

 

[jamaica]

Is the carriage piece anchored in the rear wall?

It looks like it. It goes up & rests on it as it appears.

 

[Småbrukaren]

Then it's hardly load-bearing. Remove it. Have someone jump on the stairs and see if it flexes.

 

[Småbrukaren]

Why is there plaster on the inside of the wall? How did it happen?

 

[jamaica]

Then it is hardly load-bearing. Remove it. Have someone jump on the stairs and see if it flexes.

Nice. I’ll remove it. Thanks

 

[jamaica]

Why is there plaster on the inside of the wall? How did that happen?

Don't ask me, but I would guess that the wall is a module that was installed whole and that it was clad on both sides. But I don't know. The townhouse is from '58.

 

[Småbrukaren]

If it's loose, just put it back, simply.

Regarding the module, in that case, you should have been able to access the space from another direction and wanted a nice wall.