Proposals include the requirement that all Constant Net Asset Value (CNAV) funds convert to Variable Net Asset Value (VNAV) funds, or that if they wish to remain as CNAV then they must introduce NAV buffers whereby some funds can be held back to absorb losses, along with various permutations of delays to redemptions.
The ACT submission in response explains that NAV buffers and balances at risk would completely change the nature of the investment such that most non-financial companies would no longer invest. The same would also apply on any conversion to VNAV unless the negative accounting and tax implications can be overcome.