It seems like a very small factor given the amount of HBD that would already exist. 20% would exist in HBD at that point. New HBD from rewards is 50% (HBD/HP split) of 50% (author/curator split) of 75% (reward pool) of 8% (current inflation; will be less) per year. So that's something like 1.5% per year added from printing, or 0.125% per month. Doesn't seem useful/significant to me, even in a downturn.

At the same time, we've seen it happen the other way where there is high demand for HBD but printing gets cut off and HIVE given out instead, which could dampen the market and reduce a rise in the price (which would resolve the situation in a better way).

The way I see it, in terms of current supply and demand from rewards, giving out HBD is always going to be better. If people don't want the HBD right now, it'll get sold and/or converted quickly, which ends up being essentially the same as giving out HIVE instead. If people do want the HBD, it constrains the supply of new HIVE and helps the price, which in turn helps the ratio.

It is true, however, that we still have HBD potentially available from DHF (and indeed, this is what happened before when printing was cut off with high HBD demand), which can be used to satisfy HBD demand and absorb HIVE from the market, as well as HIVE->HBD conversions (w/fee), so I guess it doesn't matter that much.