The other thing I ran into was the assets system. Neat system, but heavily limited.
I utilize the Bootstrap Icons library and the pre-bundled CSS file expects the woff and woff2 font files in the fonts/ directory relative to the bootstrap-icons.min.css file. The assets system breaks that.
Also the exposed path for assets is hardcoded to /_topcoat/assets. Not a huge fan of that. Should be configurable, IMHO.
Much like the components issue I ran into, there is no other obvious way to serve files. I ended up creating an "API route" with a custom output type to handle that. That custom output type is what gets the contents of the file to set the response body to and sets the Content-Type response header based on what type of file it is. Been working out great so far, but I need to make sure path traversal isn't possible.