[zozbot234]

> things like Wireguard require a simple, but odd procedure to request apt pull packages from newer releases

That's not a good idea, as it breaks the assurance that Debian Stable provides. Using the backports repository is the recommended approach if you need a newer version of some clearly-defined piece of software. It will pull the newer dependencies it requires from backports, while still relying on stock-provided packages as far as practicable.

[catalogia]

It's not a good idea, but Debian's wiki is nevertheless recommending it: https://wiki.debian.org/WireGuard

I tried it. Long story short, now I'm on Sid.

[XelNika]

The Wiki instructions are outdated and WireGuard has since (March 2020) come to buster-backports.