Another example of OCaml contributor accepting Github Sponsoring is Daniel Bünzli, who is the author and maintainer of many pieces of the OCaml library ecosystem, for example Cmdliner (command-line UI), Vg (declarative vector graphics), a suite of Unicode-related libraries, SDL bindings, JSON/XML libraries, Fmt (formatting), Logs for logging, Bos for shell-style stuff.
(Disclaimer: I’m part of the OCaml Software Foundation, but I’m replying here purely as myself. A previous answer about why private donations are too hard to manage for the Foundation is unfortunately still accurate.)