Do both Exceptional Friend candles replenish simultaneously?
It only seems to double your total amount. This means that you're effectively wasting fewer actions (because you can keep earning them every 10 minutes once you've reached 20).
If you manage to log on often enough to never go above 20 (which probably means you don't sleep enough ;-)), then having them would have no benefit.
I can confirm that the candles do not replenish simultanenously. The second candle doubles the total number of actions that you can accumulate, but does not increase the rate at which they accumulate.