That does not work for me. I have 8 slots with 16 memory, if I unequip the amulet with +1, one of my skills turns grey, because he does not count as memorized anymore. He may be still in the list of memorized skills but will not usable.
It has weird behavior.
I'm able to use as many as 3 more skills than I have memory for, but I'm not sure what causes some abilities to go grey after and others to stick around.
Warfare abilities seemed to almost always go grey, except for the 1st memory slot I removed.
I'll play around more and see if I can nail down what causes some abilities to stay and others to leave.
Edit:
Also, I always had +2 memory items, IDK if that affects it.
And, I have learned many more skills then what I'm attempting to equip.
Edit:
I updated my original post. I have been able to identify the consistent behavior based on the abilities I have and know. Still need more research on this exploit though, but it certainly has large abuse potential.