int32 LastCompareIndex
Tracks the last time this RepState actually replicated data. If this matches [FRepChangelistState::CompareIndex](API\Runtime\Engine\Net\FRepChangelistState\CompareIndex), then there is definitely no new information since the last time we checked.
Note, we can't solely rely on on LastChangelistIndex, since changelists are stored in circular buffers.
[FRepChangelistState::CompareIndex](API\Runtime\Engine\Net\FRepChangelistState\CompareIndex).