To make it easier and more attractive for people to bridge their BTC to iBTC, this proposal removes issue and redeem fees. The current fees are 0.15% for issues, and 0.5% for redeems. While this provides some income for vaults, the majority of vault income is through incentive rewards, so it shouldn't affect vault income too much. It is worth noting that while the bridging fees will be zero, redeems will still have the bitcoin network fees, which is a fixed amount regardless of the redeem size.
This proposal also reduces griefing collateral to 0.025%, to make it even easier to on-board new iBTC users. A reduced griefing collateral increases the risk of people creating fake issues, either as a kind of DoS attack, or to "reserve" capacity for future use. To reduce the likelihood and severity of that happening, this proposal also decreases the issue deadline from 24 hours to 12 hours.