This probably these have been discussed here, but I haven’t found them:
Tempos listed in the Absolute Tempo Change panel have specific quarter-note beat values attached to them (but the beat unit can’t be changed there). Where do these values come from? Con brio, say, at 6=120, essentially march tempo, seems to me rather lacking in “brio”. And what’s the meaning of the line at the top of that list that reads "Slower ----- ----- ----- Faster? Clicking on the bars in that line has no effect that I can see.
Once a tempo has been chosen I find that it can’t be edited, except by using the Properties box; but only the beat value can be changed there, not the beat unit, although the the words “beat unit” appear. Yes, I know I can delete the tempo text and re-enter it anew using Shift - T (in fact that workes really well, even understanding the meaning of, …5=, 6=, 7=, … etc.) But double clicking on the tempo text to edit it puts me into the note entering state, which is a bit annoying. Or have I missed something?