I have written a tutorial paper on power analyses using brms. The basic approach follows that proposed by Kruschke, but extends it in a few ways - for example, including the possibility of sequential designs/optional stopping, considering power for various effect sizes, lots of different stopping criteria, and also I think having the simulations run quite a lot more quickly than previous examples of this approach.
If anyone has feedback on the paper, please let me know. This is my first foray into more statistical/methodological papers like this, but I believe the approach I suggest generally achieves what it intends.
The written version of the paper is here:
And the full code that should be used to run the examples in the paper if desired is here: