The question in topic is If or How to answer compliments from boss at work and what I will say is that I will probably flag this as primarily opinion based as well.. It is. As per the question it asks you when flagging:
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.
I do however feel this question has been left open and edited slightly without it being closed and is now just seeking more low quality easy answers for karma. I feel like this question by now should of had something done about it, I don't want to point fingers but it feels like people overlook this when they think free reputation is available.
To clarify further on why I opened this up on meta is that over the last couple of days that I've been giving this exchange a go and seeing if I enjoy answering questions here it seems a lot of questions as a whole are low quality. Though if people jump onto the question it seemingly isn't being closed for the right reasons? Why is this? Shouldn't we as a community be closing these questions that aren't likely to go anywhere?
Furthermore editing said question to include a question again isn't helping this thread become a higher quality. "What is an appropriate way to respond when my boss compliments me over text at work?" Again this is just so subjective I could answer saying profanity and I'd at least be somewhat right? I feel like this question and the changes don't bring this up to the quality that this exchange has..
In response: A good example might be sending a thumbs up emoji on its own. Am I a better or worse person for sending that over thank you? vs the many other ways I could respond. This is just so subjective to where you work and who you work with.
The above is a good example of how this is just deeply opinon based and while 'thank you' is a great general answer it's just not a good question that should of been put on hold or closed while it came up with a better question overall.