To the OP.. Welcome to your officialness coming to FT
Who is responsible for herding large groups of clueless passengers into pre-check lines? I thought one of the purposes of pre-check was to make it a faster process for people who fly quite a bit. Yet, lately, TSA has been merging non frequent fliers in the same screening lines as frequent flyers.

I experienced a new kind of this "feature" at SEA on June 20
I am not an Alaska Airlines elite, so I did not have pre-check on my BP as I normally get with American. About 4 PM on Friday, all of the people in the premium line and some non premium passengers were sent to a special pre-check line with only one person checking ID. That one line and the normal pre-check line passengers then were directed to use both of the baggage screening lines. This,of course, slowed down the people who had expected a faster experience. Additionally, in looking at the standard, non-premium line, it moved much faster because there were more ID checkers and more screening lines.
This is not acceptable. There is no point in having dedicated lines for premium passengers if the security process is going to be slower for them.