Tag substitution ignored by reference checkout - which is it?

By default, reference checkout will pull in code that is defined in set up website >  analytics >  add to head.  This is normally fine, except it will lead to double page counts for any analytics system that  has its code in the add to head and also a tracking module in reference checkout. Until a little while ago, the solution was to use tag substitution to blank out any custom tags that are in the add to head section that you don't want to show up in the reference checkout.

Pretty recently, NetSuite silently changed how that works. Now, tag substitution is completely ignored in reference checkout.  I am seeing this in 2.03.0,  but it might also affect other versions. Of course there is nothing in the documentation either way about whether reference checkout will honor tag substitution. If it doesn't, it will take  some ugly hacks to get analytics to work on the website without doubling the page views during the checkout.