Sometimes I need to schedule a meeting slightly outside everyone's normal working hours, since we have zero timezone overlap. In these cases, it would be helpful to be reminded of entire days I am (or a colleague is) unavailable. But all-day events (which is the type that my OOO scheduling app creates by default) stay up at the top of the day, instead of covering the whole day.
It would be helpful if they stretched from top to bottom to make it clear that the person in question is unavailable. This affects both the "Meet with" and "Other calendars" features in the sidebar, and there doesn't seem to be an option about this in the settings.
Is there some easy way to fix this for good? An extension, userscript, setting I'm missing, etc.? Even an external app could work. Thunderbird's UI for this seems pretty unusable (unhelpful view and no view at all if you need to look more than 4 days in the future).