Not in the bottom scenario, your SB isn't actually in the pot yet, its just in front of you waiting for you to complete the bet, fold or raise.
in your call $200 scenario you always just place your $500 chip in front of you and let the dealer give you your $300 change.
Big no no to have players take own change, or make change from the pot willie nillie.
Keep in mind that all players should keep their Bets in front of them above the real or imaginary betting line until action concludes for that round of betting.
let the dealer make the change after action of that round has ended. this way only one person's hand is in the pot.
I am sure there are many many reasons for this. the big ones that i can think of are:
1. Keeps the math right so super easy for the dealer to know who needs change and when to give, as well as who needs to add more chips.
2. Keeps the additional time wasted in the Player A Bet $1000 with a $1000 chip, Player B Call with $1000 chip, Player C Call with $5000 chip and take 4 $1000 chips from pot, Player D Raises to $15,000 with 3 $5,000 chips scenario when Player A calls with 4 $1000 chips and 2 $5000 chips, player B folds, Player C only tosses in $10,000 more for a call because they see they have a $5,000 chip out there, and you have to remind them that they only have $1000 invested. Or deal with the help them with the math where they need to re-figure out how much to add for the call.
3. Many ways to short change the pot by accident or on purpose