From a purely semantic level, I'm not sure that your group B is any different to what the OP is suggesting is their problem: "If someone wanted a meeting, I’d

From a purely semantic level, I'm not sure that your group B is any different to what the OP is suggesting is their problem: "If someone wanted a meeting, I’d suggest a time and instead of saying, “Let me know if this works for you.” I’d switch that out for, “If not, than X time/day also works or I’m free at X time/day.” Instead of your response, the aligned with this article statement is to state a next step as a statement and forgo the question "Let's discus this further tomorrow, otherwise I'm available on Monday at midday". It's a matter of suggestion compared to questioning, These trigger different cognitions on the part of the receiver.