So the SBD locked is still counted as circulating SBD, it does affect the debt calculation.
And even though the SBD is locked, it makes sense that the debt-ratio increase, because the SBD is printed, and the debt already exists. It can't be claimed, but it exists.
Can't say more than first impressions and thoughts, because i haven't researched how the SPS work yet.
RE: How SBD peg actually works OR How the @sbdpotato conversions won't affect SBD price