As a BLM, if you have an opening in your ice phase, you can use it on someone who might not need it yet. As a RDM, I will wait until a healer drops below half. Verraise-ManaShift is a quite generous option, as it costs 45% of max MP, which means we'll go OOM in two minutes instead of four. If I did the raising, I generally expect someone else to do the shifting. Or if someone else provides a raise, I'll provide the shift. It's too expensive to do both most of the time, though.