Xref/Eglot feature requests and a question

[Gerd Möllmann]

I have a couple of feature requests regarding Xref and/or Eglot, after
switching from Lsp-mode to Eglot yesterday, which BTW went really
well. Thanks to João!

1.

I'm in a C buffer with Eglot running, and I want to go to the definition
of something whose name I know, but point is not on an identifier naming
that thing.  For instance, I want to go the definition of Lisp_Package
(in an obsure branch having a struct Lisp_Package), while point is
somewhere.

C-u M-. offers some completions, but Lisp_Package is not among them.
Not using a completion and entering Lisp_Package works.

Feature request: Could the completions be made to contain all workspace
symbols?  Lsp-mode has something doing that, and I found it quite useful
with Helm.

C-M-. Lisp_Package RET works fine, but entering a word list as
advertised in the prompt, say "Li Pa", does not.

Question: Bug or limitation?

2.

THere are some useful eglot functions that can currently only invoked
with M-x, by default.  I'm currently defining a keymap

(define-keymap :prefix 'my-eglot-bindings
  "a" 'eglot-code-actions
  "f" 'eglot-format
  "h" 'eglot-inlay-hints-mode
  "r" 'eglot-rename)

that I bind to a a prefix key in c-mode-common-hook.

Feature request: Could eglot-mode do something like that?

3.

In C mode, Xref works using Eglot, in ELisp mode it uses something else
(I have no tags tables).  Both work really well, but I apparently have
to be in an ELisp buffer to use one and in a C buffer to use the other.

Feature request: Is it possible to use more than one backend at the same
time?  So that I could C-M-. to find an ELisp function while being in a
C file?  I couldn't find something like that mentioned in the docs, so I
guess it's not yet possible.