A different idea on Bottling using auto filler and vacuum
I too had the problem of always having to adjust so a I put a tee in the vacuum line very close to where you connect it to the open/close valve. I have the carboy lower than the wine bottles so gravity doesn't take over. When I want to fill, I put my finger over the open end of the tee. When the wine gets to the fill level, I simply take my finger off the tee and proceed to the next one. The overflow bottle has very little in it. I put 16 bottles in a plastic tub in case of spillage but rarely have to wipe a few drops off.