
Blockstream is leading the development of a block size increase with a number of upcoming BIPXXX release as I understand it.
The Flexcap idea doesn't make sense to me. It seems Adam is trying to
artificially make it more expensive for miners to publish large blocks. The reason this doesn't make sense to me is that
even without a block size limit it would be more expensive for miners to publish large blocks due to the orphan cost. Why use "Flexcap" to simulate the natural supply and demand dynamics that already exist?
The fact that larger blocks are more costly to produce is illustrated in Fig. 8 of
this paper:

your beautiful graphic can't help you Peter.
you have been well advised that propagation time is not a constant and will very much improve over the years making it increasingly cheaper for miners to publish bigger blocks.