Is it bad etiquette to try to make an opponent lose on time when a position is clearly drawn? The other day I was playing a rapid game (30 minutes each side) online. I got into time trouble but I managed to convert the position into a drawn endgame. (Not just a theoretical draw—a clear draw for both sides.) In the final moments of the game, I had less than 20 seconds on my clock, and my opponent started checking me repeatedly in an attempt to make me lose on time. While I know this is standard in blitz or bullet games, I considered it to be bad form given that we were playing a slower time control. Am I right in believing this is a breach of etiquette, even if it is strictly legal?

Edit #1: Here is the final position. (I slightly misremembered what my opponent did—they weren't repeatedly checking me. Instead, they were moving their bishop around aimlessly. However, I don't think this has a huge impact on the debate. I was playing White.)

2b5/1kP1K3/8/8/8/8/8/8 w - - 16 86


Edit #2: It has been mentioned that there is another similar question that has already been asked before on the chess stack exchange. While I appreciate the similarity between these two questions, I would argue that the fact that I was playing a rapid game could have an impact on the answer. Not everyone agrees, but some people do hold this belief. Therefore, I'd like to keep this question open.
Etiquette doesn't really come into it unless your name is Gata Kamsky (strong language warning for the link). The rule is very simple. If you want flagging to be a part of the game then play with no increment, otherwise always play with an increment.