Not sure why this is down voted, I also looked into this at some point but was unable to find a solution.

MSSQL lets you save a query plan as XML then upload to another system as a hint. PG could do this using the json or xml output of EXPLAIN.

That's an interesting idea. Might be a good ability for someone to add. :)

Oracle had it for decades - ie outlines.

You could do it as an extension, but otherwise no

There are hooks for the planner and the executor, so you could force their hand quite easily with a plan extracted from a previous EXPLAIN. Being able to pass a plan at protocol level would be more efficient, for sure. I’ve worked on Postgres-XC and somewhat Postgres-XL, and that’s something that we wanted to do to generate a plan on one node, and push down the compiled plan down to other nodes to avoid the overhead of the plan computation. This stuff did that for snapshots and a few more things with an extension of the protocol.