The last time I reported the issue with multi-target buffing spells not permitting you to pick your targets correctly, I was informed that this is working as intended, and that the design choice to make your buffing (and debuffing and control - since I was reporting both this and also twin-casting hold person as well) woefully ineffective and fiddly to use like this was deliberate.
Ugh, that’s disappointing. I agree with you, the OP and everyone else who has said that these spells would be better individually targeted and it’s really annoying having to try to position characters and/or the cursor so as to try to affect who I want.