Makie/MathTeXEngine: what's the correct way for non-italic symbols in math expressions?

consider:

lines!(ax, x, y; label = L"\mathrm{d}T/dt")

which produces:

as you can see, the size of the straight d character is incorrect and larger than it should be (I think?)

What is the appropriate way to remove the italic nature of a math character? I used to use mathrm but I guess this isn’t correct.

Here’s a quick comparison screenshot of Makie/MathTeXEngine with a regularly compiled pdflatex file using the LatinModern package for the font. I tried both \text{d} and \mathrm{d}, but they appear identical as far as I can see. I’m not sure I see the ‘d’ being too big, but the font weight seems somewhat bolder in MathTexEngine.

thank you, so it appears that it just “feels” bigger to me. My bad! The circle of the d is sooo much larger in the straight version!