Non-destructive substitution was introduced in Perl 5.14 (released in 2011) so it’s not surprising you haven’t heard of it if you’ve been programming perl for years before that. Especially if you’re not always reading every single release announcement.
Hanging out on the Perl Slack and Discord channels is fun because there’s always someone out there who drops one of these kind of obscure but incredibly useful features when someone asks for help.
Despite what the OP of this thread said, I use proton through Lutris. I haven’t used any other tool for this yet, though I hear heroic games launcher is good too.
I’m not looking at it right now, but on Lutris you can add a new game, say it should run under wine, and then pick one of the versions of wine with proton.