Update: I was able to get roughly my desired behavior by editing the SendCode plugin to wrap multiline inputs with a begin...end block. I still think this should be the default behavior of the REPL (and it would presumably be pretty easy to implement) but we can’t always get what we want.
On the off chance that someone else finds this thread with the same problem, shoot me a message and I’ll share the fix with you.
P.S. I gave VS Code a shot. The way remote hosts are handled turned me off (having to install the various VS code plugins and reindex all the packages for LanguageServer.jl every time I make a new EC2 instance). But I think I will start using it for local debugging. Thanks for the tip @anon67531922!