except the people who do those scores but who carespretty sure there is not a single HalfTime-on-crazy-map player that would complain about their scores being pushed under scores of people who actually managed to pull off a passing performance on those maps in normal time.
if you're not going to unrank it, you'd need to lower the multiplier to at least 1% or lower (compared to 30% right now).
personally I feel the mod is fine to play around with and setting goals on some maps that would otherwise not be possible (I'm not talking about ranked maps in this case) so it should definitely stay, but it's just not fit for ranking. It should be in the same group as mods like relax and autopilot.
The amount of difficulty-decrease that HalfTime does on maps above 180bpm is very exponential and cannot be correctly represented with a fixed score reduction multiplier. On long-enough maps where the max combo is high enough there will always be a problem with this.