Configurable LSP client capabilities?

[phdavis1027]

Is there any interest in making client capabilities configurable? I am looking to use powernap for an LSP-MCP bridge and would like to support clients with varying capabilities. If so, I can drop a pull request, otherwise might fork for my own purposes. But I just wanted to check, since it would be totally reasonable to only care about the capabilities that Crush or Charm more generally want to support.