As an anecdotal point, I’ve been using always-on WireGuard (using a setup that’s essentially a fork of Algo) on my iPhone, iPad, and MacBook for months, via the native clients for each. I routinely hop between countries, SIM cards, WiFi networks, etc. I hit issues with Apple’s built-in captive portal detection (which has to kick in so it gives me the captive portal outside of the always-on VPN), but the WireGuard tunnel itself has been pretty much solid.