Twig template profiling?

I am trying to improve the performance of my web page. According to the debug toolbar already present in Grav, the vast majority of the time is spent in the “render” phase. I suppose this refers to the rendering of the twig templates? Is there any way to get more detailed information about this phase, i.e. which part of what template eats up the most time?

There seems to exist something like that for symfony already, but I am not exactly sure how to activate this in grav.

Thanks in advance for any help!