Marker type list order sub-optimal

[Matthew-Marks]

A very minor suggestion this! I see that the long list of marker types brought up by Add Marker is in the order given in Table 21 of ST 2067-3:2020, i.e. with the two newer groups at the bottom. I don't think the average user will know or care about the history of the markers, especially as there is no demarcation between the groups. So, maybe it would just be better to list them all in alphabetical order?

Another thought is that as they are (all?) either First Frame or Last Frame of something, you could split them into two groups and select by adding another level to the menu tree.