For facilitation of press work and release of 4th finger you don't need the whole concept...you could start with a 'cushion' or part support for the fleshy part of the palm on the thumb side...say 10-15mm high...try a little wooden piece with some felt on the top (and underneath too to protect the end plate surface).The piece could be about 30x40mm or so.
Yes, Ive seen your article and pictures. I'm going to play around with the idea of a palm support some more, but I don't want to drill any holes in or damage the finish of my concertina. I also am not currently willing to devote a whole lot of time to experimenting with this as that will mean less time I'm playing.
There were two reasons why I started removing my little finger from the rest. The first reason was it was the only way I could play some parts in Dancing With Ma Baby. The other reason is Simon Thoumire. I love his playing. After reading about his technique I started playing a little bit without using the rests. I haven't tried rotating the concertina and playing with my fingers running up & down the columns instead of across, like he does. His method of holding the instrument is very detached & free. Like you, he doesn't use the finger rest, but the rest of his technique seems very different from yours, at least as I understand it.
I really have no idea where I'll go with this.