I don't think the score will drop but I am not 100% sure. You should book another test either way and get try to get CLB10 in all modules, with CD test, you will get results in 5 days which way faster than EOR.
I have verbal and written (mail) confirmation from IELTS that their policy of score is to increase or keep it same, but to never decrease it.
I have decided however not to go for EOR after due consideration. Cut-off will increase, reaching 480 and above in all probability. But it has to come down in a month or two (3-4 draws). Judging by the pool size as per the latest information that's available, there are roughly 11K people above me. Even if FSW draws don't happen in the next 5 months, number of people @471 and above will probably not exceed 20K. Even if it does it
has to come down after 5-6 draws because above 470 isn't sustainable. Assuming CEC and PNP draws keep on going in parallel, I guess it will take maybe 3 months for that many FSW draws to take place.
Speculations aside, thinking of
474 vs 471 I can't see any exceptional benefit of this 3 CRS points. With 474 I might have to wait 1 month for cut-off to come down and with 471 I might have to wait 2 months. I just can't justify the wait time of 1-2 months extra to gamble with 10K INR. If I had the chance to get maybe 6 points in EOR I would have definitely gone for it.
Obvious things that I see in front of me to improve my score is higher degree and learning french. I don't know how long the latter is going to take but I'm hoping to start soon. Please correct me if I'm wrong in assuming in any of these.