The "HBD for commerce" is not going to happen before the rise in Hive impact rises its marketcap as well. Projecting percentages of the current marketcap is not realistic - it is the abovementioned "cap once Hive hits $2 kind of calculations" we should be making.
Personally, I doubt that is the ultimate goal.
The idea of Euro was great when you had to travel across Europe with several wallets (if done frequently) or having to spend/exchange the leftovers when leaving a country you are not going to visit soon again.
Today you have a card with access to reasonable conversion rates and the pressure is off. So is the beauty of Euro (for consumers).
Hive commerce does not need liquid HBD to be circled around. Liquid Hive and good price feeds are enough - you display USD prices but keep sending Hive around (without customers noticing).
Do the merchants feel the need to hedge their Hive holdings against USD price swings? They should. The instruments are there (the challenge is to include an easy access in the "run your commerce on Hive" package). As someone recently mentioned, even the spread of $1.00-$1.05 is uncomfortable (and I add that the common swings are going to be even outside this range as price volatility makes conversions risky at 0.99 or 1.06).
HBD as a savings asset for risk-averse entities is much more reasonable to be the primary goal. People care about investments keeping their value, they can accept a loss of value applied at the current content of the physical wallet (up to the extreme case of it being stolen). They should keep reasonable amount of Hive only (if they are uncomfortable with betting on its value going up). The HBD savings part greatly adds value to Hive experience without the need for huge supply as you target retail savers.
That being said, my shortterm play would be setting savings rate back down to allow a bit of a HBD selloff (and conversion back to Hive) to build up a cushion for the next HBD price pump ride without having to bet the extra security on the line.