The 4s reconcile tick called Apply(), which did Rows.Clear() + refill on
every tick -- resetting the user's scroll position and selection while
they're mid-read, exactly what the overlay exists to avoid.
Reconcile granularly instead: find the overlap between the previous and
latest snapshot (the ring buffer is append-mostly, evicting from the
front as entries age out of the 30-min window), trim rows for evicted
entries off the tail, and insert new entries at the head. A tick with no
change now leaves Rows untouched. The WarnErrorOnly toggle still goes
through the full Apply() rebuild, unchanged.
mika kuns
d327a1007e