Background [TL;DR]
In my previous meta question Vertical space between superscript and square root sign, I attempted (not so successfully) to illustrate a display problem about the square root sign by $\sqrt{e^\overline{X}}$
: $\sqrt{e^\overline{X}}$.
I had thought about enlarging this: ${\Huge \sqrt{e^\overline{X}}}$
: ${\Huge \sqrt{e^\overline{X}}}$, but the stroke going northeast $\nearrow$ surpasses the horizontal stroke going to the right-hand side $\to$.
Screenshot using Opera 71 on Ubuntu 20.04 LTS
MWE (min. working example)
$$\sqrt{a}$$
$$\Large{\sqrt{a}}$$
$$\Huge{\sqrt{a}}$$
$$\sqrt{a}$$ $$\Large{\sqrt{a}}$$ $$\Huge{\sqrt{a}}$$
Screenshot
Screenshot taken by Firefox 84.0.1 on Ubuntu 20.04 LTS
Expected output
The right-upward directed stroke $\nearrow$ and the horizontal stroke $\to$ are perfectly joined together as shown in the following image, but without the vertical stroke $\downarrow$.
image source: Badly scaling closing SQRT symbol with large font sizes on $\rm\TeX$.SE
\strut
or\mathstrut
, but the closest I got is\Large{\sqrt{\Huge{\mathstrut a}}}
$$\Large{\sqrt{\Huge{\mathstrut a}}}$$ which is a bit emaciated. $\endgroup$