Is there a Mouse Without Borders protocol? That's the good guy Microsoft I'd love to see.
I almost never use Synergy/Barrier/netevents (for Wayland, https://github.com/Blub/netevents) anymore but I did for a really really long time. Quite my halycon "network is thr computer" ideal world. One I hope to improve/revisit someday. (ideally when/if I ever have more space)