In the party list, whenever any member starts casting a spell, the casting bar hides their name. In many situation as a PLD, I fail to find which part member that I wish to cast Cover using <mo> macro due to the fact I can't see their names when they are casting the spell, also I don't think trying to remember where that member position in the part list is suffice.
My suggestion is to be able to hide/show their casting bar would be a really helpful is many situations.