It's hard to tell. There aren't any obvious WoG statements about the possibility, though my personal suspicion says that it might require at least some active defense which could help.
Also, Berra and Yammar are known to have Mind Delve, which appears to be the active skill used to defend the mind against ki-based and psi-based (possibly not magic-based) attacks. I don't know about Lord Vegeta, but it seems a safe bet that he has it too.
I am not particularily convinced that we need everyone we have available to incapacitate Dandeer though, so I suspect we might have at least some opportunity for trying something with a minimal opportunity cost.
I'd rather not screw around with something I know is
working in this battle. We've got enough stuff going wrong that one of the few things we know is going right (keeping Dandeer locked down and unable to concentrate) is valuable. MAYBE we could do some kind of finely calculated gambit that would be superior to the already-good outcome we have, but that's generally not a good way to fight a war. If you have a good outcome, you roll with it, exploit it, and move on to the next problem. The perfect is the enemy of the good.
I'm fairly certain that Poptart has a handle on what's a Kakara thing to do.
Seems like a pointless breach of OPSEC when we
really need to not.
I respect this, but I wanted to at least
write and suggest the idea. Having Kakara say "I'm sorry" the moment before Berra suffers terrible pain even as the mind control snaps is something that she
might or might not do. Some of us might want to take Kakara's character in that direction, especially with a family member or loved one, because we already see her developing some calluses on her sense of willingness to inflict pain on loved ones and that can go ugly places.
I'm not saying it's absolutely and unambiguously the right thing to do. But it's at least something that belongs on our list of things we MIGHT want to do.
[Also, I'm not sure what Berra could do in reaction to our "I'm sorry" without time to think and/or already knowing how the mind control spell on him works, which it seems
likely that he does not. He's smart, but that's just ridiculous. Then again, you're not wrong to at least
worry about Berra getting clued in and somehow negating what we want to do]
The problem with this one is the same that you mentioned above; it leaves Vegeta free to blast the Senzu.
We can do it in the time it takes us to IT twice. After that, Vegeta can't throw blasts at the Senzus because Dandeer is
among the Senzus. Furthermore, it is
fairly likely that Vegeta will need at least that much time to orient, understand what's going on, and power up enough to be capable of throwing a blast at the Senzus that we couldn't just deflect.
I'm not saying it's literally zero risk, NONE of our options is zero-risk, but I deem the risks low enough and the rewards high enough to be willing to support it under approval voting. Getting Jaffur back in the fight would really help, not least because he's going to feel a BAD case of "damsel in distress" syndrome after all this is over if he never gets to punch anybody.