Interviewing for a lateral position - sending a thank-you note?

I'm interviewing for a lateral position at another bank in London and I usually do not send thank-you notes as I generally think that if I don't have anything interesting to say, then it's a waste of time. Furthermore, it can come across as "weird" or desperate and I don't think it moves the needle anyway. My seniors in my current team think that reaching out with nothing substantial to say is also weird.

That being said, I had a great interview with a Syndicate Head as part of my interview process and I wanted to follow up an a topic we discussed, so I sent an email on that and asked a question or two on it. I'm coming from a very slightly different background so wanted to see how that topic differed between my coverage and his.

Is it okay to have done so? Or does it look "weird" and desperate? The reason I'm hesitating so much is that there is a weird kid at my current bank who used to work at my senior's previous bank with them, and they would reach out with very little-of-substance emails and calls and no one really liked it and found it weird. Here, however, I felt a genuine connection to the Syndicate Head and I genuinely wanted to learn some more about the topic we discussed. I didn't send it just for the sake of sending an email or for the sake of saying something for the sake of sounding smart or whatever.

Going forward, should I be sending thank-you notes in general?

Many thanks