Here's the graph. /leftypol/ with annotations. Each vertical bar is one week.
The three most notable events over this graph:>Peru elections and subsequent raids (massive rise then major dip, recovery over one week, assuming that's a full recovery)>Cuba protests (increased traffic for half a week)>coup/counter coup drama (massive spike and massive dip on leftychan, dip resuming on leftypol, recovery over two months)
Ignoring these events, it seems the /leftypol/ activity level pre-split was approximately 2040 PPD, using the pink line, ignoring both the spike of the Cuban protests and the trough caused by an error on my side (2021-08-03).
The most recent 7 days has comparable peaks and troughs compared to the old leftypol norm and activity level was approximately 1875 PPD and rising. That's 92% of the old norm, and above the average just before Chris-Chan news caused a peak.
It will be interesting to see if this recent conisistent plateaus (e.g. return to norm) or continues to rise, indicating actual growth rather than just recovery.