This has never been a possibility (at least since CBA 2006). The only thing that drops an entire block of R-days now is conflict with recurrent training. Vacation/reserve processing is either a one-for-one replacement of V and R days or the extension option. R-days removed due to buffer days are replaced during the reserve line reconstruction process.

Keep in mind, nothing you've done so far is irreversible. You can slide, unslide, extend, un-extend, waive buffers or not as many times as you want to experiment between now and close of the CIC window tomorrow.

Two dangling single R-days left on either side of the vacation may be a good thing if you're on the 777. If not, and you commute, maybe you want to re-slide, waive a buffer(s) or some other option to avoid having single R-days to commute to. The other thing is the 4 R-days removed for the buffers are going back in somewhere and that somewhere may not be the best option for you. Waive the buffers and they stay where they are.

As a commuter, maybe slide the vaca (if possible) to start on the first R-day. That way any R-days left are after your vacation in one or two blocks instead of split into singles. An added bonus is, if your vaca falls before your R-days in the month, all those vaca hours count toward leveling and push you down the list.