I’ve experimented with pick materials, thicknesses and shapes for nearly 3 decades. I am VERY impressed with the 1.5mm Honey Jar shape Torlon picks I received recently. The pick releases from the strings without much chatter/chirp but stays firmly in hand as if glued! This is especially important for someone who struggles with fine motor control and grip after having a stroke!
My one suggestion would be a return to the sharper points of the Honey Jar shapes of the past…but maybe these 1.5mm are not as sharp because they are thinner than the 2 & 3mm PEEK picks I also use.