With the current model, 12hr TWAP must be greater than 1.05$ for an expansion and must be at least greater than 1$ to issue ARTH for bond redemption.
i) Bond redemption: 12hr TWAP & 1 hr TWAP> 1$
ii) Expansion: 12 hr TWAP>1.05$
Additionally, with the latest updates, MAHA fees are charged when selling under 1$ and rewarded when buying under 1$. This is great except people can and will sell as soon as we hit the 1$ mark (avoiding any MAHA fees). Eg: A whale already managed to sell 10k ARTH when price is above 1$, completely MAHA fee-less, which quickly brought price back below peg after the introduction of additional 2500 MAHA rewards for the first 50k ARTH purchased.
We not only have to hit the 1$ mark, but actually sustain the price at 1$ or greater for 12 hr TWAP to be greater than 1$ so that ARTH can be minted and bond debts can be cleared. However, with selling fee and rewards halted at 1$, ARTH will not be able to breach the 1$ long enough for the 12hr TWAP to be greater than 1$. This has 2 implications:-
i) No ARTH minted to clear off bond debt and also no expansion
ii) Waste of MAHA rewards as the price would quickly be brought down below peg.
Change: Increase the price ceiling/floor of 1$ to 1.05$.
i) Selling below 1.05$ will be charged with MAHA fees
ii) Buying below 1.05$ will be rewarded with MAHA
Reasoning: With a higher ceiling/floor, it will be much easier for ARTH to be maintained above 1$, hence this will be easier for the protocol to mint ARTH to clear bond debts. The faster the protocol is able to clear the bond debts, the more confident and reassured the community will be.