Looks like it will take some time to figure it out, but the developer ljdawson is looking into Lemmy support for sync.
This app is so smooth, and caching posts and comments for offline use while on the plane or in low reception areas is a clutch feature for me.
It’s a third party Reddit app. My personal favourite so it’s great news.
Sync Pro is just Sync without ads, it only charged a small one-time fee. This info could be out of date as I paid for Sync Pro around ten years ago I think.