LAN sync with other clients on local network

Hello,

I'm in Africa and we have both a slow and expensive bandwidth (illimited plans are very rare). In addition, in a climate change perspective, it would be useful to limit bandwidth usage over large distances to save energy. In order to optimize this, we'd like to have the ability to sync over a LAN ~~both with the server if it's on the LAN, and especially~~ with other clients on the same LAN, who have already synced.

It is a cool and efficient existing Dropbox feature (https://help.dropbox.com/installs-integrations/sync-uploads/lan-sync-overview). And a lot of discussions have already started, both on owncloud and Nextcloud, but it looks like there's no activity anymore for years (https://github.com/nextcloud/server/issues/7092, https://github.com/nextcloud/server/issues/8331, https://github.com/owncloud/client/issues/230).

Would it be possible to consider this feature? Thank you!

For reference, other links where this feature is requested:
Nextcloud:
- https://help.nextcloud.com/t/lan-sync-please/512

owncloud:
- https://central.owncloud.org/t/lan-sync-between-clients/4205
- https://central.owncloud.org/t/gsoc-2017-fast-lan-sync/6271
- https://github.com/owncloud/core/issues/26752
- https://github.com/owncloud/client/issues/230

### Client configuration
Client version: 2.6.4stable-Win64 (build 20200303)