Good post, but inflation is more trickier than that.
The supply can double, but it doesn't manifest the price if it's not liquid. In other words if the new money doesn't enter circulation, then the price of STEEM won't halve.
Given the incentive with STEEM DOLLAR, as it gives interest ; and STEEM POWER gives interest and long term stake , we can conclude that if more people hold, which they are incentivized too, most money created won't make it to the exchanges.
So there will be a difference between monetary inflation (the amount of money created) and price inflation (the effective inflation rate observed).
Inflation is tricking down assimetrically, the same way as in the fiat economy. In fiat, it takes about 1-2 years for the inflation to fully trickle down.
I agree with your analysis, but the biggest issue I see missing from your analysis and the original authors is in relation to SMD. The money supply is also inflated by the SMD interest rate and that is liquid and not being included in the analysis.
I will have an upcoming article about SBD, currently I am researching the SP system.