DrkLvr_ makes a sound suggestion with lowering the % each year/period. I assume you would calculate a per block percentage, so the "compounded interest" would not only be per year, but would be from each block reward.
And maybe the percentages are so low compared to the time-line we are looking at.
If you're going to go into reducing the %'s each year and other complicated mechanisms, you might as well just remain at a fixed block reward. The "Keep it simple principle" holds true here. In my mind it's either a low fixed
rate (inflationary), or a fixed
block reward (disinflationary). I think we should choose between those two.
I'm fine with the fixed blocks that were planned to be implemented, but if we want to move to 0.75% - 0.9% fixed rate, I'd be OK with that too.