Not likely to be advantageous. On buckets you might get about double the sap with two taps on a LARGE tree. Typically you’ll get somewhat less than double and well under double for trees under 18” dbh. On vacuum you will definitely not get double the amount of sap from a second taphole. In many cases you’ll get about the same from two tapholes cumulatively as from one taphole, or maybe somewhat more if trees are bigger. Depends on the size of the tree and the vacuum level used.