Choosing between seatd and elogind for Wayland seat access on Artix without logind ACLs

Goal

On an Artix Linux system running OpenRC, I want to run a Wayland compositor (Sway) with the smallest possible privilege footprint, and I need to decide between the two documented seat-management options Artix ships: seatd with libseat, or the elogind fork.

Constraints and uncertainty

Because systemd-logind is absent, device permissions for DRM and input nodes fall back to group membership (seat, video, input) and udev rules rather than logind-managed ACLs. My understanding is that seatd keeps a single small root daemon holding the device file descriptors and hands them out per session, while elogind provides broader session tracking at the cost of a larger D-Bus-dependent stack. I also understand that running both at once can produce competing seat claims, so this is an either/or decision.

What is unclear to me is the practical boundary: which desktop functionality (session tracking, polkit integration, power/suspend handling) genuinely requires elogind, and which works fine with seatd plus explicit group and udev configuration.

Questions

• For a single-user Sway setup, does seatd with the seat group fully replace elogind, or are there common packages that hard-depend on logind-compatible session APIs?
• If polkit is needed for specific actions, does it function correctly under seatd-only sessions, and what extra configuration does that require?
• Is there a supported way to verify at runtime which libseat backend the compositor actually selected?