I do not agree that earning a profit (or at least minimizing losses) from conversions comes from the expense of the STEEM price. In fact in some ways that is backwards. Trading efficiently/profitably means not overpricing SBD when buying it, but it also means not underpricing STEEM when selling it. That's really the best we can do other than not converting at all which leaves the SBD oversupply unaddressed (or burning it, which I'm certainly not volunteering to do, but you are welcome to do so if you like, or maybe other witnesses with available budget).
As far as "repay" not only have all my witness power downs been spent on Steem projects and initiatives (and then some, since I am personally covering losses and plan to continue doing so for some time), I personally covered promotional and development expenses prior to the witness payments becoming significant. Nor does this account for my time or server costs (all paid out of pocket). If the STEEM price trend recovers, then perhaps someday I may be repaid by my witness business for what I have advanced, but otherwise I likely will not. This of course is all my choice, and I am very comfortable with how and how much I have contributed to the Steem community.
You might misunderstand my statement "expense of STEEM price". SBD converters sold over 350,000 STEEM last week(roughly $7,000/day), and they, including me, have a wide buffer by the feed discount that can cover 20% of STEEM price decrease per week in addition to a cheap SBD price. The main purpose of SBD discount is to compensate buyers who take risks of buying SBD at close to $1.
You are the very influential person in Steemit. If you hesitate to take some risks with SBD pegging, the community may feel dis-encouraged. Also, as a witness, while you are arguing price feed discount but you stay in a passive position at under $0.80, it would be counteractive.
This week I made about 10% from SBD conversion at my buying price is around $0.81 (because I cannot break through low sell orders). I think you can make a break-even at $0.9 or around.