The classical knob on chromatics slides is suitable firstly for manipulation by a finger tip. There are other modern variants for example with Hohner CX12. The historic Chromonica de luxe III or IV had a longer type of button incorporated in the body also. These models are more comfortable and less vulnerable than the classical kind.
Has Brendan Power or someone else got a concept for modification of the " classical" type button to achieve better ergonomy when using the finger base, the thumb, or the palm of the hand to control the slide?
I have just got the Trochilus, also with a small classical knob which is vulnerable since the instrument is "pocket-friendly"