The suggestion was made to implement a past-time limit on every block, rather than solely on the 2016 block transition periods. This approach is argued to simplify the code and enhance the logic behind difficulty adjustments, making it more universally applicable and potentially eliminating the need for restricting the actual timespan of blocks and the main reason for the Median Time Past (MTP) requirement.

However, concerns were raised about how this past-time limit proposal might not effectively remove the need for MTP. It was noted that MTP ensures a stronger sense of monotonicity by preventing each block from being more than two hours in the past relative to its predecessor. An attacker, by manipulating timestamps to move the date back by two hours for each block within a single difficulty period, could drastically reduce the difficulty for several subsequent periods by creating a negative elapsed time scenario over 24 weeks.

The conversation also touched upon the implications of removing the future time limit if a past-time limit is applied consistently across all blocks. Skepticism was expressed regarding the removal of the future time limit, as it could allow attackers to exploit the system by advancing the timestamp by an average of forty minutes per block, thereby reducing the mining difficulty by a significant factor without any real mining effort, merely by pushing the chain tip into the future.

The idea of enforcing monotonicity, or requiring that block timestamps progressively increase without regression, was debated. It was suggested that only the timestamps of the first and last block in each difficulty period should be considered for difficulty adjustments, proposing a much smaller consensus change. This minimal approach aims to mitigate potential attacks discovered while questioning the perceived benefits of introducing a two-hour past limit for all blocks and imposing monotonicity across the board. The discussion reflects a cautious stance towards sweeping consensus rule changes, advocating for more targeted modifications to address specific vulnerabilities in the mining process.