No lspace or rspace added:

$\%$ $\frac{\%}{\%}$ $\sqrt{\%}$ $\sqrt[\%]{\%}$ $\%$

$\overline{)\%}$ ${\%}_{\%}$ ${\%}^{\%}$ ${\%}_{\%}^{\%}$ $\underset{\%}{\%}$ $\stackrel{\%}{\%}$ $\underset{\%}{\overset{\%}{\%}}$

${}_{\%}{}^{\%}\%_{\%}^{\%}$ $\begin{array}{c}\%\end{array}$ $\%$ ${\%}_{\%}$

${{\%}_{\%}}_{\%}$ $\underset{\%}{\underset{\%}{\%}}$ $\frac{\frac{\%}{\%}}{\%}$

$\overline{)\%}\overline{)\%}\sqrt[\%]{\%}$ $\%$ $\%$

lspace and rspace rendered as appropriate

$\%\frac{\%}{\%}\sqrt{\%}\%$

$\left(\%\right)$ $\left(\%,\%\right)\overline{)\%\%}{\%}_{\%}{\%}^{\%}{\%}_{\%}^{\%}\underset{\%}{\%}\stackrel{\%}{\%}\underset{\%}{\overset{\%}{\%}}$

${}_{\%}{}^{\%}\%_{\%}^{\%}\begin{array}{c}\%\%\end{array}\%{\%}_{\%}{\%\%}_{\%}$

${{\%}_{\%}}_{\%}\underset{\%}{\underset{\%}{\%}}\frac{\frac{\%}{\%}}{\%}$

$\%\%\%$ $\%\%$ $\%\%$