I've always found building/running your app code on OpenBSD (even if it's not your target OS) - makes for a better app overall because of how strict OpenBSD is - it forces your app to run "correctly" more than any other OS.
I've been able to find and fix way more app bugs, than when I ran my software on other OS'es
Any specific examples? I don't daily drive Linux but that sounds interesting.
Somewhat related, for Minecraft (Bedrock, C++) we compile with a ton of different tool chains and I really appreciate Clang versus MSVC for how strict the compiler can be (even with /-permissive).
Ted Unangst’s “Developing Software in a Hostile Environment” talk from EuroBSDcon 2019 is a good start. Controlling malloc(3) behaviour with malloc.conf to catch initialisation and Use After Free bugs is a great example from there.
Personally, a different userland and directory structure usually also beats out Linux-isms.
I've been able to find and fix way more app bugs, than when I ran my software on other OS'es