In my first playthrough of Fire Emblem Three Houses, I learned that not only support conversations can be prevented due to the story not progressing far enough, but can also be locked out for progressing the story too far. Presumably, this is due to support conversations no longer making sense after certain story events take place, and are met with a "you've missed your opportunity to deepen this bond" message in the support menu.
With subsequent playthroughs in mind, that leads me to a couple of questions...
Is there a list of characters & supports that are missable due to story progression (with spoilers in mind, it'd be preferable for listing the chapter number, not the story event, where the support gets locked out)?
Does the house/story path you chose matter in determining if/when a support becomes missable? Are there supports that are missable only for a specific house?