It is important to realize that chess is a zero-sum game*. In other words, everything that gives advantage to one player gives an equal disadvantage to the other player. So if adding 2 minutes to your opponent's clock is benefits you, then it would be harmful to your opponent. It is not possible for any decision of arbiter to give an advantage to your opponent and a slight advantage to you too.

(* Although of course there are things that make both players enjoy the game more etc., but here I'm concerned only about the result of the game.)

Suppose two minutes are added to your opponent's clock. Now (s)he has two choices (or something between them):

1. Pretend his extra two minutes didn't exist and play as in his clock showed 2 minutes less.
2. Take good use of his extra time.

If your opponent chooses option 1, the only effect of the extra time is that he does not run out of time accidentally. This never gives any advantage to you. If your opponent thinks that option 2 is better for him than option 1, then he also believes that him choosing option 2 is worse for you.

It is possible that your opponent does not understand how well you use his time and therefore chooses option 2 but it ends up being beneficial to you. However, I think this is very unlikely.

I think a more important loophole is this: When calling the arbiter to settle any dispute over the board, you are allowed to stop the clock even if it is your turn. Sometimes it can take a minute or two before the arbiter arrives, so it can be used as a way to gain extra thinking time. For example, in a difficult position in time trouble, you can claim a draw (even if you know there's no draw) and gain extra time while waiting for the arbiter.

Because the usual penalty for unreasonable claims is adding time to your opponent's clock, you may gain more advantage by the extra thinking time than you lose by the penalty. Needless to say, this is extremely unsportsmanlike, and will result in everyone hating you and possibly even point losses if the arbiter sees through. Please don't ever do this.

It is important to realize that chess is a zero-sum game*. In other words, everything that gives advantage to one player gives an equal disadvantage to the other player. So if adding 2 minutes to your opponent's clock benefits you, then it would be harmful to your opponent. It is not possible for any decision of the arbiter to give an advantage to your opponent and a slight advantage to you too.

(* Although of course there are things that make both players enjoy the game more etc., but here I'm concerned only about the result of the game.)

Suppose two minutes are added to your opponent's clock. Now (s)he has two choices (or something between them):

1. Pretend his extra two minutes didn't exist and play as if his clock showed 2 minutes less.
2. Make good use of his extra time.

If your opponent chooses option 1, the only effect of the extra time is that he does not run out of time accidentally. This never gives any advantage to you. If your opponent thinks that option 2 is better for him than option 1, then he also believes that him choosing option 2 is worse for you.

It is possible that your opponent does not understand how well you use his time and therefore chooses option 2 but it ends up being beneficial to you. However, I think this is very unlikely.

I think a more important loophole is this: When calling the arbiter to settle any dispute over the board, you are allowed to stop the clock even if it is your turn. Sometimes it can take a minute or two before the arbiter arrives, so it can be used as a way to gain extra thinking time. For example, in a difficult position in time trouble, you can claim a draw (even if you know there's no draw) and gain extra time while waiting for the arbiter.

Because the usual penalty for unreasonable claims is adding time to your opponent's clock, you may gain more advantage by the extra thinking time than you lose by the penalty. Needless to say, this is extremely unsportsmanlike, and will result in everyone hating you and possibly even point losses if the arbiter sees through it. Please don't ever do this.