Different bellows constructions...butterflies or others...

The material - paper, cardboard, leather of course makes a difference but regarding measures I have noticed at least 4 variants:

1.1 Oldish style bellows seem to have generally a cross section ( transverse "diameter" 5-10mm smaller than the endplates
1.2 Later makers seemingly more often make the bellows as wide as the endpalte. Volume increases this way and if similar materials are used I think the flexibility mostly is less than with 1.1. This may be an advantage or a disadvantage depending on what you want of course. IF using straight pumping you want the bellows rather rigid and stable - if praactising fanning greater flexibility is demanded. Opinions?
2.1 The depth of the folds may vary. Oldish style bellows mostly had deeper folds I think
2.2 Later makers seem to use less deep folds which also mostly makes the bellows more solid/stable.

Generally oldish style bellows ( 1.1 and 2.1 ) thus are "floppier" than modern ones. I think this is very important to keep in mind and also to conscíously choose the type of bellows construction suitable for individual/occasional playing method and musical idiom.

Somwe examples:
I would suggest that for energetic Morris style Anglo playing 1.2 and 2.2 would be preferable since you mostly play standing with a rhythmical bounce and a great deal of stability is needed.
I would also suggest that for Irish style single note Anglo playing - mostly performed seated and with playing fluent melodic phrases and less forcibly than the Morris idiom - a flexible bellows and using the fanning technique may be advantageous.
What do Anglo players say about this?

Dick - do you think your "butterfly bellows" may be something like the combination of 1.1 and 2.1 ?