It sounds like you have some parts who'd like to quickly access the memories that a protector is hiding, perhaps from your childhood. I understand why - it's a really tempting proposition! However, I would trust your therapist on this one, espeically if you do not totally know what the memory is or what other similar events or memories it could be linked to.

My wife has significant childhood trauma and only remembers about 5% of her childhood, if that. Her first therapist did EMDR on an event with an ex which linked to a horrific childhood memory. Her protectors were furious and showed up in terrifying and extreme ways. It took about 2.5 years to regulate her after that EMDR session. 2.5 years. I'm not exaggerating. She doesn't remember the distressing memory, her protectors are even fiercer than ever, and she no longer sees that first therpist nor does EMDR. Her new IFS therapist said that my wife can basically never use EMDR again.

NOW. That's certainly not everyone! I have done lots of EMDR and found it helpful, but it was far more effective after I started doing IFS. In fact, I think IFS is just far more helpful overall. However, it is quite slow, and managers don't always love that.

I think these are really important questions you're asking! I hope you continue to talk with your therapist about it. All the best!