Re: [O] Make beamer items ticked or alerted via overlay?

[Fraga, Eric]

Yes, it is possible to use overlays in org beamer export.

Depending on what you want to achieve, there are a number of ways to do
this.  One way in to introduce LaTeX directives directly.  For instance,

#+begin_src org
  1. The first point
  2. The second one @@latex:{\only<2->\checkmark}@@
  3. the third point
#+end_src

There are also other examples in section 13.8.4 (Beamer specific syntax)
in the info manual.

HTH.
-- 
Eric S Fraga via Emacs 27.0.50, Org release_9.2.4-401-gfabd6d