Latex equations like the following
U(y,\mu)\underbrace{\int q(x)\text{d}x}_{=1} + \frac{1}{2}U_{xx}(y,\mu)\underbrace{\int q(x)(x-\mu)^2\text{d}x}_{=\sigma_q^2}
will not render the underbraces properly. This is the result in Obsidian 0.9.4:
This had already been reported here and it seems to go away by increasing the zoom level, but that is not really convenient.