“Anchor + Offset” is stable because the anchor param should uniquely identify a specific record from which the offset is applied; a sort-order, direction, and page-size may also be optimally specified.

It is when you do "?after=uuid" or "?after=timestamp".

Actually newest first shouldn't be a problem, you need only to point to "last seen date" (up to ms precision)

An algorithmically "curated" TL, yes that's harder