When I apply these patches and add a hook
(add-hook 'eglot-managed-mode-hook #'eglot-inlay-hints-mode)
and try to delete a buffer, I get
eglot--error: [eglot] Can't turn on `eglot-inlay-hints' mode.
once, and then I am able to delete the buffer.
This is due to an unrelated bug that I've also fixed
in the emacs-29 branch.
Anyway, the "inlay hints" feature is now also installed.
I hope you can test it and report any bugs. You sohuld
be able to use that one-liner to enable eglot-inlay-hints-mode
automatically.
João