Most Ergonomic Thumb Cluster Style?

[taako]

I am designing a keyboard primarily based on Kinesis Advantage 2. I am going to be using flexible PCB like the actual
Advantage2 to get the bowl shape but might add in a few more keys like where the Ergodox places them.

I am considering re-designing the thumb clusters but want to know what would be the best alternative.

The two biggest alternatives i'm thinking of are:
 - Thumb arcs like Keyboardio
 - Clusters on a sloped opposable plane like the Manuform

Any other designs i should consider?

[JianYang]

- Thumb arcs like Keyboardio
 - Clusters on a sloped opposable plane like the Manuform

This is exactly what I wanted to say.

I guess the best option would be manuform main cluster with a clay (or detatchable 3d printed) thumb cluster to experiment and find what suits you best. Come to think of it - a detachable thumb cluster would have the added advantage of being easily changeable later on. You will most likely want to change something in the long term...

[vvp]

I think maltron/kinesis thumb clusters are best if you use significantly higher keycaps on more far away keys. The movement down is easier for me than pressing to a side. And it is possible to fit more thumb keys in them and the keyboard can be flatter overall for easier moving around. For a completely flat keyboard the thumb arc is probably the best.

Oobly has a nice version of opposing thumb clusters:
https://geekhack.org/index.php?topic=49721.msg1077640#msg1077640