In the spirit of selfhosting, you can also host headscale. Its an open source implementation of the proprietary tailscale control plane.
It allows you to get over the 5 device limit (different depending on tiers), as well as keep your traffic on your devices. And, imo, it is pretty stable.
The only issue is that the control plane (by nature) has to be publically accessible. But imo it’s way less of a security target than a massive app like nextcloud.