Great to see the progress.
Is increasing the haircut rule percentage still planned? I have been reading some concerns about that (especially after seeing the collapse of UST), so I was wondering if it would make sense for the blockchain to have a hard upper limit, but for the witnesses to be able to set a lower limit at will. So the witnesses would be able to bring the haircut rule limit as low as they want (if need be), but they cannot move it above the hard limit set by the blockchain itself. In this way, they would be able to quickly react and stop a potential systemic collapse from happening, if such a threat ever arises.
The code change for raising the haircut percentage from 10 to 30% was made a while back in the develop branch (i.e. it is part of the hardfork changes). I don't believe there is any major risk at 30%. Also, I believe the change will increase HBD liquidity and reduce risk for HBD holders, and I believe this will have knock-on positive benefits for Hive holders as well.
With a small value like 30%, I don't think it is a good idea to allow it to be lowered by witnesses. It is more work and I think making it a runtime-changeable variable would dramatically increase the uncertainty involved in investing in HBD, to the detriment of the entire mechanism.