Need a little help here -

I have 7 days of vacation in March (the last week of the bid month), and I was awarded a RA+ line that has zero days in the last week. Now, I plan to extend the vaca by 3 days, but I'm curious if there is any advantage to sliding it in order to knock out more RA+ days? If I do nothing but extend 3 days to the left and keep the buffer, I'll only knock out 3 RA+ days, but I could slide it to the left and knock out several more, so....
1. Is it a moot point? My understanding of the CBA is that if I knock out less than 10 R days, CRS will automatically remove extra R days to make the total 10?
2. Will my vaca bank be reduced by 10*4.6 CH regardless of how many R days are in direct conflict?

Thanks!
SM