That is actually a tricky one. I've never used a portfolio tracking tool. I just have a spreadsheet that I input share counts and total dollar amounts. It factors in withdrawals/deposits/etc and gives you a return.
I think people try to complicate this a bit too much. The way my dividends are tracked is they're deposited in cash in my accounts. Then, when I buy something with them eventually, they're added to my total dollar amount, which my portfolio would not factor in as a deposit, so it would add to my overall return.
However, I am someone who pays 0 attention to the dividends I am receiving. I do know lots like to track their dividends.
I know Snowball Analytics is a pretty user friendly platform but I am not sure it's going to give you want you want in terms of different starting dates, DCA buys etc. However, it might. I have never actually used the platform myself.
The one I think MIGHT actually do what you want it to do is Sharesight. However, it is quite expensive, I think around $250 CAD a year.