Sorry, my internet is not working this morning. Since he has been going between these doses (2.25u and 2.5u), you might want to follow the rule for cats who don't hold reductions that is he will earn a reduction only if he drops 3 times between 40 and 50 on 3 separate days. A drop below 40 would however be a reduction.
It's hard to say. He might bounce from last night's limes. He was almost blue by +2 last night. If you are home, you could get a +2.5 or +3 and know if he is continuing to drop hard or has slowed down.