If DRIP is enabled, Stock Events will adjust your number of shares and average purchase price after the dividend has been paid out. The closing price of the dividend payout day will be used. This doesn't apply to past and estimated dividends.
If you use the transactions mode, Stock Events will create a dividend transaction for you.
Tax settings are applied before determining the amount of shares to add. If your dividend payout would be 100$ and you have a tax setting of 25%, we will use 75$ to calculate the amount of shares.
You can enable DRIP for each individual stock.